STUDY DESIGN: Secondary analysis of a cohort enrolled in a prospective, randomized, longitudinal clinical trial. OBJECTIVES: The single-step test (SST) was evaluated to assess its intertester reliability, validity as a test of activity limitation, and responsiveness to change for patients after unilateral total knee arthroplasty (TKA). The SST was also examined to determine whether it could differentiate between the surgical and nonsurgical lower limbs of patients after unilateral TKA and between the surgical limbs of patients after TKA and the limbs of healthy controls. BACKGROUND: Tests of functional ability for patients recovering from TKA cannot differentiate the contribution of each limb to performance outcome. A test of unilateral limb ability would provide a metric for assessing the surgical lower extremity, without the confounder of the status of the contralateral lower extremity. METHODS: Intertester reliability was assessed between clinicians and between a clinician and a switch mat. Patients who underwent unilateral TKA were tested at initial outpatient physical therapy evaluation, at 3 months after TKA, and at 1 year after TKA. RESULTS: The assessment of function with the SST was determined to be reliable between testers when using a stopwatch. SST times were significantly correlated with other measures of lower extremity functional performance, providing evidence of its validity in patients after TKA. The SST was responsive to treatment in patients after TKA, with improvements in time for test completion. Performance on the SST also differed between limbs of patients after TKA and when comparing the limbs of healthy controls to those of patients after TKA. CONCLUSION: The SST is a reliable measure between testers and a valid and responsive test of activity limitations when assessing unilateral lower extremity impairments in patients after TKA.

J Orthop Sports Phys Ther 2013;43(2):66-73. Epub 16 November 2012. doi:10.2519/jospt.2013.4372

KEY WORDS: function, joint replacement, knee, osteoarthritis

STUDY DESIGN: Longitudinal cross-sectional study. BACKGROUND: In the early stages after total knee arthroplasty (TKA), quadriceps strength of the operated limb decreases and is substantially less than that of the nonoperated limb. This asymmetry in strength is related to asymmetrical movement patterns that increase reliance on the nonoperated limb. Over time, quadriceps strength in the operated limb increases but remains less than that in age-matched controls without knee pathology, whereas the quadriceps strength in the nonoperated limb gradually decreases. The purpose of this study was to investigate the changes in quadriceps strength and function of both limbs up to 3 years after TKA and to evaluate change in interlimb kinematic and kinetic parameters over time compared to that in age-matched individuals without knee pathology. METHODS: Fourteen individuals after TKA and 14 healthy individuals matched for age, weight, height, and sex participated in the study. Outcome measures included kinematics, kinetics, quadriceps strength, and functional performance. RESULTS: In participants who underwent TKA, quadriceps strength was significantly different between limbs at 3 months and 1 year after TKA, but not at 3 years after TKA. In this group, there was also a significant improvement in self-reported function between 3 months and 1 year after TKA, but a significant decrease between years 1 and 3 for the physical component summary score of the Medical Outcomes Study 36-Item Short-Form Health Survey. In the TKA group, there were few interlimb differences in joint kinematics and kinetics 3 years after TKA, which may be attributed to a combination of worsening in the nonoperated limb, as well as improvement in the operated limb. Differences between participants without knee pathology and those 3 years after TKA still existed for kinematic, kinetic, and spatiotemporal variables. CONCLUSION: As interlimb differences in quadriceps strength decrease after TKA, there are concomitant symmetrical improvements in temporospatial and kinetic gait parameters. The symmetry 3 years after TKA in quadriceps strength is primarily the result of progressive weakness in the nonoperated limb.

J Orthop Sports Phys Ther 2012;42(12):1039-1049, Epub 22 October 2012. doi:10.2519/jospt.2012.3763

KEY WORDS: biomechanics, joint replacement, walking

STUDY DESIGN: Descriptive prospective cohort study. OBJECTIVES: To investigate the relationships between knee joint effusion, quadriceps activation, and quadriceps strength. These relationships may help clinicians better identify impaired quadriceps activation. BACKGROUND: After anterior cruciate ligament (ACL) injury, the involved quadriceps may demonstrate weakness. Experimental data have shown that quadriceps activation and strength may be directly mediated by intracapsular joint pressure created by saline injection. An inverse relationship between quadriceps activation and the amount of saline injected has been reported. This association has not been demonstrated for traumatic effusion. We hypothesized that traumatic joint effusion due to ACL rupture and postinjury quadriceps strength would correlate well with quadriceps activation, allowing clinicians to use effusion and strength measurement as a surrogate for electrophysiological assessment of quadriceps activation. METHODS: Prospective data were collected on 188 patients within 100 days of ACL injury (average, 27 days) referred from a single surgeon. A complete clinical evaluation of the knee was performed, including ligamentous assessment and assessment of range of motion and effusion. Quadriceps function was electrophysiologically assessed using maximal volitional isometric contraction and burst superimposition techniques to quantify both strength and activation. RESULTS: Effusion grade did not correlate with quadriceps central activation ratio (CAR) (zero effusion: mean ± SD CAR, 93.5% ± 5.8%; trace effusion: CAR, 93.8% ± 9.5%; 1+ effusion: CAR, 94.0% ± 7.5%; 2+/3+ effusion: CAR, 90.6% ± 11.1%). These values are lower than normative data from healthy subjects (CAR, 98% ± 3%). CONCLUSION: Joint effusion after ACL injury does not directly mediate quadriceps activation failure seen after injury. Therefore, it should not be used as a clinical substitute for electrophysiological assessment of quadriceps activation. Patients presenting to physical therapy after ACL injury should be treated with high-intensity neuromuscular electrical stimulation to help normalize this activation.

J Orthop Sports Phys Ther 2012;42(6):502-510, Epub 20 April 2012. doi:10.2519/jospt.2012.3793

KEY WORDS: ACL, effusion, electrophysiological assessment, swelling

SYNOPSIS: The management of patients after anterior cruciate ligament reconstruction should be evidence based. Since our original published guidelines in 1996, successful outcomes have been consistently achieved with the rehabilitation principles of early weight bearing, using a combination of weight-bearing and non-weight-bearing exercise focused on quadriceps and lower extremity strength, and meeting specific objective requirements for return to activity. As rehabilitative evidence and surgical technology and procedures have progressed, the original guidelines should be revisited to ensure that the most up-to-date evidence is guiding rehabilitative care. Emerging evidence on rehabilitative interventions and advancements in concomitant surgeries, including those addressing chondral and meniscal injuries, continues to grow and greatly affect the rehabilitative care of patients with anterior cruciate ligament reconstruction. The aim of this article is to update previously published rehabilitation guidelines, using the most recent research to reflect the most current evidence for management of patients after anterior cruciate ligament reconstruction. The focus will be on current concepts in rehabilitation interventions and modifications needed for concomitant surgery and pathology. LEVEL OF EVIDENCE: Therapy, level 5.

J Orthop Sports Phys Ther 2012;42(7):601-614, Epub 8 March 2012. doi:10.2519/jospt.2012.3871

KEY WORDS: ACL, graft, surgery

STUDY DESIGN: Case report. BACKGROUND: Rehabilitation that includes progressive quadriceps strengthening after total knee arthroplasty (TKA) leads to superior outcomes. Though patients with TKA show marked functional improvement after outpatient physical therapy, they continue to adopt movement asymmetries characterized by reduced knee excursion on the operated limb and excessive loading on the contralateral limb. The purpose of this case report was to describe the functional and biomechanical improvements in a patient who, after TKA, participated in a novel physical therapy protocol that included retraining of symmetrical movement patterns. CASE DESCRIPTION: A 57-year-old female with unilateral knee osteoarthritis was evaluated prior to TKA and at 3 and 10 weeks after surgery. Postoperative rehabilitation included progressive quadriceps strengthening and movement retraining that consisted of visual, verbal, and tactile feedback to promote symmetrical weight bearing during strengthening exercises and functional activities. Outcomes were compared to a historical cohort of patients with TKA. OUTCOMES: Prior to TKA, the patient scored below average on all functional measures and walked with knee biomechanics that were abnormal and asymmetrical. After symmetry retraining, her knee motion and moments were restored to normal levels. The patient also walked with greater magnitude and more symmetrical knee excursion compared to a cohort of similar patients. DISCUSSION: This case report describes the use of a novel rehabilitation protocol intended to improve walking biomechanics and functional outcomes after TKA. Restoration of symmetrical movement patterns could improve long-term outcomes of TKA. Further research is needed to evaluate the effectiveness and implementation of similar rehabilitation strategies in a wide range of patients after TKA. LEVEL OF EVIDENCE: Therapy, level 4.

J Orthop Sports Phys Ther 2012;42(2):135-144. doi:10.2519/jospt.2012.3773

KEY WORDS: motion analysis, osteoarthritis, physical therapy, rehabilitation, total knee replacement

This month’s issue of JOSPT contains a bibliometric analysis of the publishing history of the Journal of Orthopaedic & Sports Physical Therapy. The results provide an opportunity to reflect on trends at JOSPT and, more generally, in the evidence base of orthopaedic and sports physical therapy practice. Results of the bibliometric review by Coronado and colleagues are encouraging for JOSPT and the profession of physical therapy as a whole. The results indicate an increase in the publication of research articles involving symptomatic subjects, with fewer narrative and nonsystematic review papers. The results also raise an interesting issue about whether we have a sufficient number of randomized controlled trials in our literature and to what extent our future progress should be based on the publication of more randomized trials.

J Orthop Sports Phys Ther 2011;41(12):907-908. doi:10.2519/jospt.2011.0110

KEY WORDS: evidence-based medicine, physical therapy, profession, randomized controlled trials

Anterior cruciate ligament (ACL) injuries commonly occur with negative sequelae, including reduced activity in the short term and threats to long-term knee health. Nonoperative management of highly active individuals after ACL rupture is controversial. A recent randomized controlled trial, comparing structured rehabilitation and early surgery with structured rehabilitation and optional delayed surgery, demonstrated no significant differences between the 2 groups in patients' self-reported knee function 2 years after inclusion. Work identifying individuals with an anterior cruciate ligament-deficient knee as copers and noncopers demonstrates considerable potential for success of nonoperative treatment in selected patients. However, the story is still incomplete. Many questions still need to be answered before we can prospectively, and with strong predictive ability, identify patients who can regain knee function with structured rehabilitation and no reconstructive surgery.

J Orthop Sports Phys Ther 2011;41(10):706-707. doi:10.2519/jospt.2011.0108

KEY WORDS: anterior cruciate ligament, copers, noncopers

STUDY DESIGN: Prospective cohort study without a control group. OBJECTIVES: Firstly, to present our 5-week progressive exercise therapy program in the early stage after anterior cruciate ligament (ACL) injury. Secondly, to evaluate changes in knee function after completion of the program for patients with ACL injury in general and also when classified as potential copers or noncopers, and, finally, to examine potential adverse events. BACKGROUND: Few studies concerning early-stage ACL rehabilitation protocols exist. Consequently, little is known about the tolerance for, and outcomes from, short-term exercise therapy programs in the early stage after injury. METHODS: One-hundred patients were included in a 5-week progressive exercise therapy program, within 3 months after injury. Knee function before and after completion of the program was evaluated from isokinetic quadriceps and hamstrings muscle strength tests, 4 single-leg hop tests, 2 different self-assessment questionnaires, and a global rating of knee function. A 2-way mixed-model analysis of variance was conducted to evaluate changes from pretest to posttest for the limb symmetry index for muscle strength and single-leg hop tests, and the change in scores for the patient-reported questionnaires. In addition, absolute values and the standardized response mean for muscle strength and single-leg hop tests were calculated at pretest and posttest for the injured and uninjured limb. Adverse events during the 5-week period were recorded. RESULTS: The progressive 5-week exercise therapy program led to significant improvements (P<.05) in knee function from pretest to posttest both for patients classified as potential copers and noncopers. Standardized response mean values for changes in muscle strength and single-leg hop performance from pretest to posttest for the injured limb were moderate to strong (0.49-0.84), indicating the observed improvements to be clinically relevant. Adverse events occurred in 3.9% of the patients. CONCLUSION: Short-term progressive exercise therapy programs are well tolerated and should be incorporated in early-stage ACL rehabilitation, either to improve knee function before ACL reconstruction or as a first step in further nonoperative management. LEVEL OF EVIDENCE: Therapy, level 2b.

J Orthop Sports Phys Ther 2010;40(11):705-721, Epub 6 August 2010. doi:10.2519/jospt.2010.3345

KEY WORDS: ACL, adverse events, copers, hop tests, noncopers

The Orthopaedic Section of the American Physical Therapy Association presents this fifth set of clinical practice guidelines on knee pain and mobility impairments, linked to the International Classification of Functioning, Disability, and Health (ICF). The purpose of these practice guidelines is to describe evidence-based orthopaedic physical therapy clinical practice and provide recommendations for (1) examination and diagnostic classification based on body functions and body structures, activity limitations, and participation restrictions, (2) interventions provided by physical therapists, (3) and assessment of outcome for common musculoskeletal disorders.

J Orthop Sports Phys Ther 2010:40(6):A1-A35. doi:10.2519/jospt.2010.0304

The reviewer list on page A1 and the Affiliations and Contacts on page A31 of the original article were amended in the September 2010 Erratum, and the article PDF with the Erratum page included is provided here. Please see: September 2010 Erratum

KEY WORDS: APTA, clinical practice guidelines, ICD, ICF, Orthopaedic Section

The Orthopaedic Section of the American Physical Therapy Association presents this fourth set of clinical practice guidelines on knee ligament sprain, linked to the International Classification of Functioning, Disability, and Health (ICF). The purpose of these practice guidelines is to describe evidence-based orthopaedic physical therapy clinical practice and provide recommendations for (1) examination and diagnostic classification based on body functions and body structures, activity limitations, and participation restrictions, (2) interventions provided by physical therapists, (3) and assessment of outcome for common musculoskeletal disorders.

J Orthop Sports Phys Ther 2010;40(4):A1-A37. doi:10.2519/jospt.2010.0303

KEY WORDS: APTA, clinical practice guidelines, ICD, ICF, Orthopaedic Section

STUDY DESIGN: Randomized clinical trial. OBJECTIVES: Determine effective interventions for improving readiness to return to sports postoperatively in patients with complete, unilateral, anterior cruciate ligament (ACL) rupture who do not compensate well after the injury (noncopers). Specifically, we compared the effects of 2 preoperative interventions on quadriceps strength and functional outcomes. BACKGROUND: The percentage of athletes who return to sports after ACL reconstruction varies considerably, possibly due to differential responses after acute ACL rupture and different management. Prognostic data for noncopers following ACL reconstruction is absent in the literature. METHODS: Forty noncopers were randomly assigned to receive either progressive quadriceps strength-training exercises (STR group) or perturbation training in conjunction with strength-training exercises (PERT group) for 10 preoperative rehabilitation sessions. Postoperative rehabilitation was similar between groups. Data on quadriceps strength indices [(involved limb/uninvolved limb force) × 100], 4 hop score indices, and 2 self-report questionnaires were collected preoperatively and 3, 6, and 12 months postoperatively. Mann-Whitney U tests were used to compare functional differences between the groups. Chi-square tests were used to compare frequencies of passing functional criteria and reasons for differences in performance between groups postoperatively. RESULTS: Functional outcomes were not different between groups, except a greater number of patients in the PERT group achieved global rating scores (current knee function expressed as a percentage of overall knee function prior to injury) necessary to pass return-to-sports criteria 6 and 12 months after surgery. Mean scores for each functional outcome met return-to-sports criteria 6 and 12 months postoperatively. Frequency counts of individual data, however, indicated that 5% of noncopers passed RTS criteria at 3, 48% at 6, and 78% at 12 months after surgery. CONCLUSION: Functional outcomes suggest that a subgroup of noncopers require additional supervised rehabilitation to pass stringent criteria to return to sports. LEVEL OF EVIDENCE: Therapy, level 2b.

Note: If watching the first video, we recommend downloading and referring to the accompanying PowerPoint slides for any text that is not readable.

J Orthop Sports Phys Ther 2010;40(3):141-154, Epub 30 January 2010. doi:10.2519/jospt.2010.3168

KEY WORDS: ACL, knee, outcomes measures, rehabilitation

STUDY DESIGN: Clinical measurement. OBJECTIVE: To determine the interrater reliability of a knee joint effusion grading scale in an outpatient orthopaedic physical therapy clinic. BACKGROUND: Knee joint effusion may indicate joint inflammation or irritation. Therefore, objective monitoring of effusion is important to decision making regarding patient prognosis and program progression. The clinicians in the authors' clinic use a modified stroke test to assess for knee joint effusion, which is operationally based on a 5-point grading scale. METHODS: Seventy-five patients (44 male, 31 female) receiving outpatient physical therapy for a unilateral knee problem, for whom effusion assessment was indicated, were tested. The subjects ranged from 16 to 65 years of age. Pairs of therapists graded the knee joint effusion using the clinical grading scale. A contingency table was constructed and analyzed using Cohen kappa values to establish interrater reliability. Percent agreement was also calculated. RESULTS: The kappa value was 0.75, observed as a proportion of the maximum possible kappa, and the percent agreement was 73%. Fifty-four of 75 pairs of tests had perfect agreement. Only 5 had disagreement of 2 grades, and there were no disagreements of greater than 2 grades. CONCLUSION: These findings provide evidence to support the proposed clinical effusion grading scale as a reliable method to assess knee joint effusion between therapists in an outpatient orthopaedic physical therapy clinic in patients with unilateral knee dysfunction. Only 5 of 75 ratings resulted in disagreement that could result in different clinical decisions being made by the therapists.

J Orthop Sports Phys Ther 2009;39(12):845-849, Epub 15 October 2009. doi:10.2519/jospt.2009.3143

KEY WORDS: hydroarthrosis, measurement, swelling, tibiofemoral

Twenty healthy adults were positioned in sitting on an isokinetic dynamometer. Maximum voluntary isometric knee extension torque was determined. Subsequently, two 10-sec, maximally tolerated contractions were elicited with each machine. The order of stimulation was randomized and there were 2-minute rest periods between contractions. Electrically elicited torque values were expressed as a percentage of the maximal voluntary isometric torque (%MVIT).

Analysis of variance with one repeated measure showed a significant difference among %MVIT produced by the stimulators. NMES 2 (Nemectrodyn 7) produced significantly less %MVIT than either NMES 1 (Electrostim 180-2) or NMES 3 (Chattanooga VMS). In all but three cases, NMES 2's maximal current output was reached. Although all three devices were capable of producing %MVIT that has been shown to be sufficient for strengthening, it appears that NMES 2 does not have the capacity to provide "overload" as strength increases.

J Orthop Sports Phys Ther 1989;10(8):297-301.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: First, to classify a group of individuals with an anterior cruciate ligament (ACL)-deficient knee as potential copers or potential noncopers, based on an established screening examination. Second, to prospectively follow a cohort of individuals with an ACL injury and characterize the nonoperatively treated subjects as true copers and true noncopers 1 year after injury, and evaluate the outcomes in operatively treated individuals 1 year after ACL reconstruction. Finally, to calculate the predictive value of the screening examination based on a 1-year follow-up of the group of subjects with ACL tears treated nonoperatively. BACKROUND: A screening examination has been developed for early classification of individuals with ACL injuries. Potential copers have successfully been identified as rehabilitation candidates and have shown that they are able to continue preinjury activities without ACL reconstruction (true copers). However, the potential of individuals identified as noncopers to become true copers has not been studied. METHODS AND MEASURES: One hundred and twenty-five subjects with ACL injury were evaluated using a screening examination consisting of 4 single-legged hop tests, the Knee Outcome Survey activities of daily living scale, the global rating of knee function, and the numbers of episodes of giving way. Knee laxity measurements, the international knee documentation committee subjective knee form (IKDC2000), and return to sport were included as outcome measurements. RESULTS: Thirty-seven percent (n = 46) of the subjects with ACL injury were classified as potential copers at the screening examination. Of the 102 subjects examined at follow-up, 51% (n = 52) had undergone nonoperative treatment. Sixty-five percent (n = 34) of the nonoperated subjects were classified as true copers at the 1 year follow-up. Among the potential copers, 60% were true copers, while 70% of the subjects initially classified as potential noncopers were true copers at the 1 year follow-up. The positive predictive value for correctly classifying true copers at the screening examination was 60% (95% confidence interval: 41%-78%), while the negative predictive value was 30% (95% confidence interval: 16%-49%). CONCLUSION: A majority (70%) of subjects classified as potential noncopers were true copers after 1 year of nonoperative treatment. Individuals with nonoperative treatment and ACL reconstruction showed excellent knee function and were highly active at the 1 year follow-up. The prognostic accuracy of this screening examination for correctly classifying true copers was poor. LEVEL OF EVIDENCE: Prognosis, level 1b.

J Orthop Sports Phys Ther. 2008;38(10):586-595, published online 18 July 2008. doi:10.2519/jospt.2008.2750

KEY WORDS: ACL, knee, copers, screening, surgery

A 19-year-old male soccer player presented with pain in the right anterolateral proximal leg region 5 days after injury. Despite negative plain radiographs and lack of joint deformity there was suspicion of an anterolateral proximal tibiofibular joint dislocation that spontaneously reduced. Magnetic resonance imaging (MRI) confirmed the diagnosis of a recent dislocation.

J Orthop Sports Phys Ther. 2008;38(2):87. doi:10.2519/jospt.2008.0402

KEY WORDS: proximal tibiofibular dislocation

J Orthop Sports Phys Ther. 2008;38(2):36-41, published online 7 September 2007. doi:10.2519/jospt.2008.2609

The purpose of this case problem was to describe an uncommon presentation and treatment of a patient with posterolateral corner instability. Table 1 of the article summarizes the physical therapy interventions and physical therapy goals for this patient. Posterolateral corner damage is typically concomitant with injury to the posterior cruciate ligament (PCL) or anterior cruciate ligament (ACL). This patient was unique because she injured the posterolateral corner in combination with a grade II lateral collateral ligament (LCL) sprain. Additionally, an uncommon feature presenting in this patient’s case was the perceived abnormal position of the fibular head. As in most knee injuries, quadriceps weakness was a major contributor to her functional level, thereby making strengthening exercises a cornerstone of treatment. In the clinical management of this patient, reassessment throughout the course of physical therapy, multiplane proprioceptive exercises, and a comprehensive home exercise program (HEP) were helpful in returning the patient to her prior level of function.

J Orthop Sports Phys Ther. 2003; 33(4):185-195.

Key Words: posterolateral corner instability, posterior cruciate ligament, anterior cruciate ligament

Muscles operate eccentrically to either dissipate energy for decelerating the body or to store elastic recoil energy in preparation for a shortening (concentric) contraction. The muscle forces produced during this lengthening behavior can be extremely high, despite the requisite low energetic cost. Traditionally, these high-force eccentric contractions have been associated with a muscle damage response. This clinical commentary explores the ability of the muscle-tendon system to adapt to progressively increasing eccentric muscle forces and the resultant structural and functional outcomes. Damage to the muscle-tendon is not an obligatory response. Rather, the muscle can hypertrophy and a change in the spring characteristics of muscle can enhance power; the tendon also adapts so as to tolerate higher tensions. Both basic and clinical findings are discussed. Specifically, we explore the nature of the structural changes and how these adaptations may help prevent musculoskeletal injury, improve sport performance, and overcome musculoskeletal impairments.

J Orthop Sports Phys Ther. 2003;33(10):557-571.

Key Words: muscle action, plyometrics, strength

Study Design: A case series. Objectives: The purpose of this case series was to assess the effect of high-intensity neuromuscular electrical stimulation (NMES) on quadriceps strength and voluntary activation following total knee arthroplasty (TKA). Background: Following TKA, patients exhibit long-term weakness of the quadriceps and diminished functional capacity compared to age-matched healthy controls. The pain and swelling that results from surgery may contribute to quadriceps weakness. The use of high-intensity NMES has previously been shown to be effective in quickly restoring quadriceps strength in patients with weakness after surgery. Methods and Measures: All patients were treated for 6 weeks, 2 to 3 visits per week, in outpatient rehabilitation. Five patients (NMES group) participated in a voluntary exercise program for both knees and NMES for the weaker knee. Three patients (exercise group) participated in a voluntary exercise program for both knees without NMES. For each treatment session, 10 isometric electrically elicited muscle contractions were administered at maximally tolerated doses to the initially weaker leg of the NMES group. Quadriceps strength and muscle activation were repeatedly assessed up to 6 months after surgery using burst superimposition techniques. Results: At 6 months, the weak NMES-treated legs of 4 of 5 patients in the NMES group had surpassed the strength of the contralateral leg. In contrast, none of the weak legs in the exercise group were stronger than the contralateral leg at 6 months. Changes in quadriceps muscle activation mirrored the changes exhibited in strength. Conclusion: When NMES was added to a voluntary exercise program, deficits in quadriceps muscle strength and activation resolved quickly after TKA.

J Orthop Sports Phys Ther. 2004;34(1):21-29. doi:10.2519/jospt.2004.0947

Key Words: geriatric, inhibition, rehabilitation, total knee replacement

We will discuss the mechanisms by which dynamic knee stability may be achieved and relate this to issues that interest clinicians and scientists concerned with dynamic knee stability. Emphasis is placed on the neurophysiologic evidence and theory related to neuromuscular control. Specific topics discussed include the ensemble firing of peripheral mechanoreceptors, the potential for muscle stiffness modulation via force and length feedback, postural control synergies, motor programs, and the neural control of gait. Factors related to answering the difficult question of whether or not knee ligament injuries can be prevented during athletic activities are discussed. Prevention programs that train athletes to perform their sport skills in a safe fashion are put forth as the most promising prospect for injury prevention. Methods of assessing neuromuscular function are reviewed critically and the need for future research in this area is emphasized. We conclude with a brief review of the literature regarding neuromuscular training programs.

J Orthop Sports Phys Ther. 2001;31(10):546-566.

Key Words: knee, stability

Anterior knee pain is a common complaint, occurring in approximately 1 of 4 people; individuals involved in athletics report an even higher incidence. The condition is more common in women than men and most often affects younger persons, with a peak incidence between the ages of 10 and 35 years. Symptoms include the following: pain in the knee when ascending and descending stairs, when squatting, or with prolonged sitting; swelling; a popping or grinding sensation; and incidences of the knee buckling or giving way. Often termed patellofemoral pain syndrome (PFPS), the spectrum of symptoms varies greatly from one individual to another (eg, achy pain after a long run or severe pain when rising from a chair). Many patients with anterior knee pain are eventually referred to rehabilitation. Although PFPS is one of the most common clinical conditions treated by orthopaedic and sports physical therapists, a consensus as to how these patients should be managed does not exist. Subtle variations in symptoms (and the attribution of symptoms to a variety of different causes) deem it unlikely that a generic protocol for treatment or exercise prescription can be developed for the entire scope of individuals experiencing PFPS. Differential diagnosis must consider a range of inflammatory conditions, mechanical problems, and other conditions (eg, tendinitis and bursitis, patellar hypermobility, subluxation and dislocation, posterior cruciate ligament tear, plica, loose bodies, reflex sympathetic dystrophy, osteochondritis dissecans, systemic arthritis, muscle strain, stress fracture, meniscal tear, neuroma, tumor, and iliotibial band syndrome). A variety of techniques have been advocated for treatment of PFPS. Some of these techniques include nonsteroidal anti-inflammatory drugs, ice, quadriceps strengthening, stretching, patella taping or bracing, and orthotics; however, if we simply treat the inflammatory process without treating the underlying cause, the condition will ultimately become chronic or recurrent. Conversely, if we attempt to treat the malalignment without addressing the inflammatory process first, a chronic complaint of pain may result. Any exercise or technique that recreates pain might perpetuate inflammation. A technique that works in one instance may not work in another. The chronicity of the disorder, level of pain and inflammation, activity level, and lower extremity alignment should all be considered when developing a management strategy. Treatment and exercise programs must be based on specific signs and symptoms of each individual. The purpose of this report, therefore, is to illustrate the diagnostic process in the development of a treatment plan for a patient with anterior knee pain after meniscal surgery.

J Orthop Sports Phys Ther. 2000;30(3):138-142.

Key Words: patellofemoral pain syndrome, treatment, malalignment

Nonoperative management of anterior cruciate ligament (ACL) rupture has not been a successful option for those who participate in high-level physical activity. However, there are instances when patients may want to attempt to return to physically demanding activities with nonoperative rehabilitation for an ACL injury. The purpose of this commentary is to describe guidelines for nonoperative management of physically active individuals with ACL injuries who wish to return to preinjury levels of physical activity. The guidelines are based on the results of 2 clinical studies that improved the overall success of nonoperative management of physically active individuals with ACL ruptures. A decision-making process for selecting appropriate candidates for nonoperative management (rehabilitation candidates) is described. Individuals are classified as rehabilitation candidates if they have no concomitant ligament or mensical damage associated with the ACL injury, have a unilateral ACL injury, and meet all 4 of the following criteria: (1) timed hop test score of 80% or more of the uninjured limb, (2) Knee Outcome Survey Activities of Daily Living Scale score of 80% or more, (3) global rating of knee function of 60% or more, and (4) no more than 1 episode of giving way since the incident injury to the time of testing. Individuals meeting the criteria of a rehabilitation candidate undergo an intensive rehabilitation program before returning to high-level activity. The rehabilitation program consisting of lower extremity muscle strength training, cardiovascular endurance training, agility and sport-specific skill training, and a training program using balance perturbations is described.

J Orthop Sports Phys Ther. 2000;30(4):194-203.

Key Words: anterior cruciate ligament, knee, rehabilitation

Study Design: Descriptive study of phenomenon. Objectives: To determine the extent of failure of voluntary activation of the quadriceps femoris muscle in patients early after patellar contusion. Background: Pain and effusion are related to the presence of quadriceps inhibition. We hypothesized that patients with patellar contusions would be unable to fully recruit their quadriceps muscles and that the activation deficit would be associated with self-report measures of function. Methods and Measures: Sixteen patients who had sustained a unilateral patellar contusion fewer than 4 months prior to testing participated in the study (7 men, 9 women; mean age = 30.0 ± 11.6). Subjects completed a self-report questionnaire to assess knee function and performed an isometric burst superimposition test on the involved and uninvolved quadriceps at 60° of knee flexion. The subjects were assigned to 2 groups according to the presence (n = 5) or absence (n = 11) of quadriceps inhibition. Results: Sixty-nine percent of the subjects tested were able to fully activate their quadriceps. Both groups had a decreased knee extensor force on the involved side compared to the uninvolved, but the group with inhibition had a lower side-to-side percentage of knee extensor force (mean = 65.5% ± 18.9) than those without inhibition (mean = 85.5% ± 16.4). Conclusion: Early after patellar contusion, approximately one-third of the patients demonstrated quadriceps inhibition. According to our working hypothesis, the majority of the patients tested should have demonstrated inhibition. Quadriceps inhibition was not associated with the activities of daily living, sports activity, or global rating scales in this study. Decreased volitional quadriceps force production (the hallmark of inhibition) was the only variable that discriminated patients with patellar contusion who had inhibition from those who did not.

J Orthop Sports Phys Ther. 2000;30(11):654-663.

Key Words:knee function, patellar contusion, patellofemoral joint injury, quadriceps strength, reflex quadriceps inhibition

Study Design: Case report. Background: To present the rehabilitative course, decision-making, and clinical milestones that allowed a top-level professional soccer player to return to full competitive activity 90 days after surgery. Case Description: The patient was a 35-year-old forward player who sustained an isolated complete tear of the left anterior cruciate ligament (ACL) in the midst of the competitive 2001-2002 season. He was in contention for a position on the Italian World Cup Team that was to be played 135 days after his injury, only if he demonstrated that he could return to play at the highest level before the team was selected. The patient underwent an arthroscopically assisted ACL reconstruction with a double-loop semitendinosus-gracilis autograft 4 days after the injury. Eight days after surgery he began rehabilitation at a rate of 2 sessions a day, 5 days a week, plus 1 session every Saturday morning. These sessions were performed in a pool for aquatic exercises, in a gymnasium for flexibility, coordination, and strength exercises, and on a soccer field for recovery of technical and tactical skills, with continuous monitoring of training intensity. Outcomes: The surgical technique and the progressive rehabilitation program allowed the patient to play for 20 minutes in an official First Division soccer game 77 days after surgery and to play a full game 90 days after surgery. Eighteen months postsurgery, the player had participated in 62 First Division matches, scoring 26 times, and had received no further treatment for his knee. Discussion: This case report suggests that early return to high-level competition after ACL reconstruction is possible in some instances. Some factors that may have favored the early return include optimal physical fitness before surgery, a strong psychological determination, an isolated ACL lesion, a properly placed and tensioned graft, a personalized progression of volume and intensity of exercise loads, and an appropriate density of rehabilitative training consisting of a mix of gymnasium, pool, and field exercises.

J Orthop Sport Phys Ther. 2005;35(2):52-66. doi: 10.2519/jospt.2005.1583

Key Words: ACL, knee, rehabilitation, semitendinosus

Patients are commonly referred to physical therapy for work-related mechanical low back pain (LBP). Technological advances (eg, diagnostic imaging) for identifying pathology of the spine have not decreased the time period in which symptoms resolve nor do they guide physical therapy treatment. Treatment of low back pain is often influenced by the bias of individual physical therapists, and care is often based on unproven techniques. The patient's distress and illness behavior, socioeconomic and job status, previous surgeries, and chronicity of LBP can influence the outcome of treatment, but there is little evidence to support the correlation between structural pathophysiology identified by diagnostic testing and the disability status of patients with LBP. Medical diagnosis (eg, herniated nucleus pulposis, spondylolisthesis) has not been helpful in directing successful rehabilitation of patients with LBP. Identifying the exact tissues responsible for the LBP, therefore, should not be the goal of clinical assessment. Several studies suggest that an assessment-based treatment scheme provides a better outcome than a nonspecific treatment approach. Selection of assessment-based treatments depends on both the patient's history and an elucidation of the movements and mechanical stresses that reproduce the patient's symptoms. Recent research has supported the concept of prescribing exercise by matching the therapy to the motions that cause or relieve symptoms. The goal of exercise prescription based on repeated motion testing of the spine is to use the findings of the exam and movement testing to create a specific program to restore function. This rational approach to exercise prescription should theoretically result in faster resolution of symptoms and shorter episodes of care than nonspecific exercise programs. The purpose of this article is to demonstrate the usefulness of a classification system, described by Delitto et al, for determining appropriate treatment in a patient with recent onset of LBP and to describe how the diagnostic process influenced treatment choices.

J Orthop Sports Phys Ther. 1999;29(9):534-539.

Key Words: assessment-based treatment, exercise

Shoulder pain and dysfunction with overhead activities resulting from subacromial impingement syndrome is common. Subacromial impingement syndrome has generally been classified as primary or secondary. A thorough history and physical examination are essential to identifying the etiology of the subacromial impingement syndrome and to direct treatment. Primary subacromial impingement syndrome, resulting from mechanical encroachment into the subacromial space usually by an acromial hook or spurs, occurs in middle age. Individuals with primary subacromial impingement syndrome have symptoms of shoulder pain and weakness with overhead activities. Impingement tests (eg, Neer, Hawkins) are positive. Typically, external rotation, flexion, and abduction of the shoulder are weak and painful. Night pain, usually an inability to sleep on the painful shoulder, is a common symptom of the full-thickness rotator cuff tears that can also occur in this age group. Trauma is usually the mechanism of injury. Persons with secondary subacromial impingement syndrome also have symptoms of pain and weakness with overhead activities. These individuals are usually young and often participate in sports that require repetitive overhead motion (eg, baseball, swimming, volleyball). Symptoms with secondary impingement are attributed to rotator cuff tendinitis. These symptoms are thought to result from overuse of the rotator cuff tendons to compensate for subtle anterior or multidirectional glenohumeral instability. More recently, scapulothoracic muscle weakness has been identified as a cause of secondary subacromial impingement syndrome. Here, the lack of scapular stability is thought to contribute to secondary subacromial impingement syndrome.

J Orthop Sports Phys Ther. 1999;29(1):31-38.

Key Words: shoulder pain, subacromial, tendinitis

Study Design: Prospective study with repeated measures. Objectives: The overall goal of this investigation was to describe the time course of recovery of impairments and function after total knee arthroplasty (TKA), as well as to provide direction for rehabilitation efforts. We hypothesized that quadriceps strength would be more strongly correlated with functional performance than knee flexion range of motion (ROM) or pain at all time periods studied before and after TKA. Background: TKA is a very common surgery, but very little is known regarding the influence of impairments on functional limitations in this population. Methods and Measures: Forty subjects, who underwent unilateral TKA followed by rehabilitation, including 6 weeks of outpatient physical therapy, were studied. Testing occurred at 5 time periods: preoperatively, and at 1, 2, 3, and 6 months after surgery. Test measures included quadriceps strength, knee ROM, timed up-and-go test, timed stair-climbing test, bodily pain, and general health and knee function questionnaires. Results: Subjects experienced significant worsening of knee ROM, quadriceps strength, and performance on functional tests 1 month after surgery. Quadriceps strength went through the greatest decline of all the physical measures assessed and never matched the strength of the uninvolved limb. All measures underwent significant improvements following the 1-month test. Quadriceps strength was the most highly correlated measure associated with functional performance at all testing sessions. Conclusions: Functional measures underwent an expected decline early after TKA, but recovery was more rapid than anticipated and long-term outcomes were better than previously reported in the literature. The high correlation between quadriceps strength and functional performance suggests that improved postoperative quadriceps strengthening could be important to enhance the potential benefits of TKA.

J Orthop Sports Phys Ther. 2005;35(7):424-436. doi:10.2519/jospt.2005.2036

Key Words: disability, muscle, outcome, replacement

Knee ligament arthrometers are used during rehabilitation to assess changes in knee laxity after anterior cruciate ligament injury. This study investigated the reliability and error associated with measurements of knee laxity using 3 different instrumented devices: the KT-2000, the Knee Signature System (KSS), and the Genucom Knee Analysis System to aid in the interpretation of instrumented laxity measurements during rehabilitation. Ten subjects with unilateral anterior cruciate deficiency were examined by 2 testers on 2 separate days. Measurement error was calculated as the minimum difference required to assume a true change in laxity between 2 measurements (p<.05). Between-day reliability was relatively high for both the KSS and the KT-2000 (0.95 and 0.83, respectively) but substantially lower for the Genucom (0.22). Intertester reliability was slightly lower for the KT-2000 and the KSS (0.92 and 0.78, respectively) and slightly higher but still low for the Genucom (0.27). When monitoring changes in anterior laxity of an anterior-cruciate-deficient knee, the following error values were determined to be needed in order to assume a true difference between successive measurements: KT-2000, 2.0 mm; KSS, 4.2 mm; and Genucom, 5.9 mm. The results of this study suggest that measurements of anterior laxity taken by a single examiner using the KT-2000 provide the most reliable measurements.

J Orthop Sports Phys Ther. 1994;19(6):345-351.

Key Words: anterior cruciate ligament, joint laxity, reliability

Study Design: Case report.
Background: Long-term deficits in quadriceps femoris muscle strength and impaired muscle activation are common among individuals with total knee arthroplasty (TKA). Failure to address strength-related impairments results in poor surgical and functional outcomes, which may accelerate the progression of osteoarthritis in other lower extremity joints. The purpose of the current case report was to implement a neuromuscular electrical stimulation (NMES) treatment protocol in conjunction with an intense weight-training program, with the aim of reversing persistent quadriceps muscle impairments after TKA.
Case Description: The patient was a 62-year-old male cyclist 12 months following simultaneous, bilateral TKA with impairments in left quadriceps strength and volitional muscle activation. His left quadriceps strength was 26% weaker than his right and central activation ratio (CAR) of his left quadriceps was 13% lower than his right quadriceps CAR. NMES to the left quadriceps was implemented for 6 weeks, in addition to an intense volitional weight-training program with emphasis on unilateral lower extremity exercises.
Outcomes: The patient demonstrated a 25% improvement in left quadriceps femoris maximal volitional force output following 16 treatments of combined NMES and volitional strength training over a 6-week period. The patient’s volitional muscle activation improved from a CAR of 0.83 before treatment to 0.97 after treatment. At discharge from physical therapy and at his 18-month postoperative follow-up, the patient’s left quadriceps strength was only 4% lower than his right quadriceps strength. At the 24-month follow-up, the patient’s left quadriceps strength was 6% stronger than his right quadriceps strength.
Discussion: The patient was able to achieve symmetrical quadriceps strength and complete muscle activation following 6 weeks of NMES and volitional strength training. An intense strengthening program may have the potential to reverse persistent strength-related impairments following TKA.

J Orthop Sports Phys Ther. 2006;36(9):678-685. doi:10.2519/jospt.2006.2305

Key Words: joint replacement, muscle strength, rehabilitation