STUDY DESIGN: A descriptive and exploratory investigation of lumbar extensor performance in persons with a recent history of single-level microdiscectomy. OBJECTIVE: To provide a justification for and outline the procedure of assessing lumbar extensor musculature performance. BACKGROUND: The time of holding an unsupported trunk horizontally, also called the Sorensen Test (ST), is often used to test the lumbar extensor endurance of healthy and patient populations, but may need to be modified for some patients. METHODS AND MEASURES: Sixty-eight participants completed a modified ST procedure, along with several questionnaires and performance measures, approximately 4 to 6 weeks after a single-level microdiscectomy. Participants were classified as either able to complete or unable to complete the final position of the modified ST procedure (trunk horizontal). RESULTS: Fifty-one point five percent of the participants could not attain the final position of the modified ST procedure due to either pain or perceived exertion. Those who could not attain the final position of the modified ST procedure had significantly lower scores (compared to those who could) on most measures. A majority (78.8%) of the participants in this study who were unable to complete the ST were correctly classified using the Fear-Avoidance Belief Questionnaire Work Subscale and a 24-hour activity questionnaire. CONCLUSION: The ability to attain the final position of the modified ST procedure was closely associated with fear-avoidance beliefs and physical activity level, suggesting that this test may be too intense (either real or perceived) for many patients within 4 to 6 weeks following a single-level microdiscectomy.

J Orthop Sports Phys Ther. 2007;37(7):356-363; published online 29 May 2007. doi:10.2519/jospt.2007.2366

KEY WORDS: Fear-Avoidance Belief Questionnaire, lumbar musculoskeletal performance, Sorensen test

STUDY DESIGN: Case report. BACKGROUND: Following total knee arthroplasty (TKA), restoration of normal quadriceps muscle function is rare. One month after surgery, quadriceps torque (force) is only 40% of preoperative values and quadriceps activation is only 82% of preoperative levels, despite initiating postoperative rehabilitation the day after surgery. Early application of neuromuscular electrical stimulation (NMES) offers a possible approach to minimize loss of quadriceps torque more effectively than traditional rehabilitation exercises alone. CASE DESCRIPTION: A 65-year-old female underwent a right, cemented TKA. Isometric quadriceps and hamstrings muscle torque were measured preoperatively and 3, 6, and 12 weeks after TKA. Quadriceps muscle activation was measured using a doublet interpolation technique at the same time points. The patient participated in a traditional TKA rehabilitation program augmented by NMES, which was initiated 48 hours after surgery and continued twice/day for the first 3 weeks, and once daily for 3 additional weeks. OUTCOMES: Preoperatively, the involved quadriceps produced 75% of the torque of the uninvolved side and demonstrated only 72.9% activation. At 3, 6, and 12 weeks after TKA, quadriceps torque was greater than the preoperative values of the involved side by 16%, 40% and 56%, respectively. Similarly, activation improved to 93.4%, 94.6%, and 93.5% at 3, 6, and 12 weeks after TKA. DISCUSSION: Mitigating quadriceps muscle weakness immediately after TKA using early NMES may improve functional outcomes, because quadriceps weakness has been associated with numerous functional limitations and an increased risk for falls. Despite presenting preoperatively with substantial quadriceps torque and activation deficits, the patient in this case demonstrated improvements in quadriceps function at all time points measured, all of which were superior to those reported in the literature.  The patient also made substantial improvements in functional outcomes, including the Knee Injury and Osteoarthritis Outcome Score (KOOS), 6-minute walk test, timed up and go (TUG) test, stair-climbing test, and the SF-36 Physical Component Score. Appropriately controlled clinical trials will be necessary to determine whether such favorable outcomes following TKA are specifically attributable to the addition of NMES to the rehabilitation program. 

J Orthop Sports Phys Ther. 2007, 37(7):364-371, published online 29 May 2007. doi:10.2519/jospt.2007.2541

KEY WORDS: electrical stimulation, knee replacement, muscle activation, rehabilitation

J Orthop Sports Phys Ther. 2007;37(7):372-379, published online 16 April 2007. doi:10.2519/jospt.2007.2440

KEY WORDS: muscle architecture, tendon compliance, ultrasound

STUDY DESIGN: Preassessment and postassessment of treatment intervention. OBJECTIVE: To determine the changes in pain and disability secondary to shoe lift intervention for subjects with chronic low back pain (LBP) who have a limb length inequality (LLI). BACKGROUND: Previous reports have suggested that LLI may be a cause of LBP. Most prior studies of lift therapy for management of LLI in patients with LBP have lacked clear guidelines for clinicians regarding the implementation of shoe lift intervention. METHODS AND MEASURES: Twelve subjects (6 male, 6 female) between the ages of 19 and 62 years with LLI (6.4-22.2 mm) and chronic LBP (1-30 years) participated. Visual analog scale (VAS) pain ratings and disability questionnaire scores were acquired before and after lift intervention. Subjects determined their lift height based on resolution of LBP symptoms. RESULTS: Subjects experienced relief of general pain symptoms (P = .0006) and pain associated with standing (P = .002) following lift intervention, with minimally clinically important (MCID) reductions in general pain for 9 of 12 subjects and MCID reductions in standing pain for 8 of 10 subjects.   Subjects also had less disability on the disability questionnaire (P = .001) following the intervention, with 9 of 12 subjects experiencing MCID reductions in disability. CONCLUSION: Shoe lifts may reduce LBP and improve function for patients who have chronic LBP and an LLI. Randomized controlled trials are needed to assess the efficacy of this intervention. 

J Orthop Sports Phys Ther. 2007;37(7):380-388, published online 29 May 2007. doi:10.2519/jospt.2007.2429

KEY WORDS:  leg length inequality, low back pain, rehabilitation

STUDY DESIGN: Descriptive, cohort design. OBJECTIVES: To comprehensively examine sex differences in clinical measures of static lower extremity alignment (LEA). BACKGROUND: Sex differences in LEA have been included among a myriad of risk factors as a potential cause for the increased prevalence of knee injury in females.  While clinical observations suggest sex differences in LEA exist, little empirical data are available to support these sex differences or the normal values that should be expected in a healthy population. METHODS AND MEASURES: The right and left static LEA of 100 healthy college-age participants (50 males [mean ± SD age, 23.3 ± 3.6 years; height, 177.8 ± 8.0 cm; body mass, 80.4 ± 11.6 kg] and 50 females [mean ± SD age, 21.8 ± 2.5 years; height, 164.3 ± 6.9 cm body mass, 67.4 ± 15.2 kg]) were measured. Each alignment characteristic was analyzed via separate repeated-measures analyses of variance, with 1 between-subject factor (sex) and 1 within-subject factor (side). RESULTS: There were no significant sex-by-side interactions and no differences by side. Females had greater mean anterior pelvic tilt, hip anteversion, quadriceps angles, tibiofemoral angles, and genu recurvatum than males (P<.0001). No sex differences were observed in tibial torsion (P = .131), navicular drop (P = .130), or rearfoot angle (P = .590). CONCLUSION: Sex differences in LEA indicate that females, on average, have greater anterior pelvic tilt, thigh internal rotation, knee valgus, and genu recurvatum. These sex differences were not accompanied by differences in the lower leg, ankle, and foot. Understanding these collective sex differences in LEA may help us to better examine the influence of LEA on dynamic knee function and clarify their role as a potential injury risk factor.

J Orthop Sports Phys Ther. 2007;37(7):389-398, published online 16 April 2007. doi:10.2519/jospt.2007.2487

KEY WORDS: malalignment, posture, risk factor assessment

STUDY DESIGN: Randomized controlled prospective experimental study. OBJECTIVES: To examine the effects of transcutaneous low-voltage microamperage stimulation (LVMAS) on the mechanical strength of Achilles tendon repair in rats at 4 weeks after injury. BACKGROUND: Understanding the effect of LVMAS on the healing of injured tendons is hampered by the lack of related experimental studies, especially from the aspect of biomechanical outcome measures. METHODS AND MEASURES: Fourteen, 3-month-old, male Sprague-Dawley rats received surgical transection to the medial portion of their right Achilles tendon. The rats were divided into a LVMAS group (n=7) and control group (n=7). From day 6 post-surgery onwards, the LVMAS group received daily treatment of transcutaneous LVMAS (2.5 V, 100 μA/cm², 10 pulses per second, positive current) for a total of 22 sessions, while the control group received placebo LVMAS by the same investigator during that period. On day 31, the Achilles tendons were harvested for biomechanical testing for load relaxation, stiffness, and ultimate tensile strength along the longitudinal direction. RESULTS: The normalized Achilles tendon ultimate tensile strength of the LVMAS group (mean ± SD, 110.5% ± 25.0%) was higher than the control group (75.3 ± 20.8%) (P=.014), but no significant difference was found in normalized stiffness and load relaxation between the 2 groups (P=.239 and .350, respectively). CONCLUSION: The results of this study suggest that the administration of transcutaneous LVMAS could improve healing and consequently the tensile strength of partially transected Achilles tendons of rats at 4 weeks after injury.

J Orthop Sports Phys Ther. 2007;37(7):399-403, published online 16 April 2007.  doi:10.2519/jospt.2007.1412

KEY WORDS: asymmetrical biphasic, biomechanical testing, electrical stimulation, tendon injuries

STUDY DESIGN: Case series. CASE DESCRIPTION: Four patients who had developed knee extension motion loss following anterior cruciate ligament reconstruction were referred to physical therapy for treatment. They were treated with drop-out casting and completed a Lower Extremity Functional Scale at baseline, at the time of application of the drop-out casting, and at discharge. OUTCOMES: Three males and 1 female with a mean age of 20.5 years (range, 18-22 years) were referred to physical therapy a mean of 31 days (range, 19-49 days) following bone-patella tendon-bone autograft anterior cruciate ligament reconstruction. The mean number of physical therapy sessions attended was 29.5 visits (range, 20-47 visits). The mean improvement in knee extension range of motion (ROM) and knee flexion ROM prior to the application of drop-out casting was 4.3^o (range, -1^o to 10^o) and 24.3^o (range, 0^o to 40^o), respectively. The mean improvement on the Lower Extremity Functional Scale was 10.3 points prior to drop-out casting. At time of discharge, the total mean improvement in knee extension ROM loss was 11.0^o (range, 4^o to 15^o), knee flexion ROM was 30.8^o (range, 22^o to 35^o), and Lower Extremity Functional Scale was 12 points (range, -5 to 21 points). Two of the patients were able to complete a running program without difficulty, while the other 2 patients had difficulty with higher-level activities. DISCUSSION: Despite the low incidence of knee extension ROM loss following surgery, the inability to achieve full knee extension does occur and can have debilitating consequences. When early emphasis of full passive knee extension has been inadequate, these results suggest that improving knee extension motion without inhibiting knee flexion motion is possible with the use of a drop-out cast. Future research should focus on comparison of drop-out casting to dynamic splinting, as well as the optimal frequency and duration of low-load long-duration stretching using a drop-out cast.

J Orthop Sports Phys Ther. 2007;37(7):404-411, published online 29 May 2007. doi:10.2519/jospt.2007.2466

KEY WORDS:  arthrofibrosis, knee extension lag, splinting, stiff knee

Letters to the Editor-in-Chief of the JOSPT as follows:

• Letter regarding the article, Does Evidence Support the Existence of Lumbar Spine Coupled Motion? A Critical Review of the Literature. J Orthop Sports Phys Ther. 2007:37(7):412. doi:10.2519/jospt.2007.0205.
• Authors' Response. J Orthop Sports Phys Ther. 2007:37(7):412-413. doi:10.2519/jospt.2007.0206.
• Letter regarding the article, The Effect of Anterior Versus Posterior Glide Joint Mobilization on External Rotation Range of Motion in Patients With Shoulder Adhesive Capsulitis. J Orthop Sports Phys Ther. 2007:37(7):413. doi:10.2519/jospt.2007.0207.
• Authors' Response. J Orthop Sports Phys Ther. 2007:37(7):414-415. doi:10.2519/jospt.2007.0208.