STUDY DESIGN: Randomized clinical trial. OBJECTIVES: To determine the efficacy of trunk balance exercises for individuals with chronic low back pain. BACKGROUND: The majority of exercises focusing on restoring lumbopelvic stability propose targeting the feedforward control of the lumbopelvic region. Less attention has been paid to feedback control during balance adjustments. METHODS: Seventy-nine patients were randomly allocated to 2 different groups. The experimental group performed trunk balance exercises in addition to standard trunk flexibility exercises. The control group performed strengthening exercises in addition to the same standard trunk flexibility exercises. The primary outcome measures were pain intensity (visual analogue scale), disability (Roland-Morris Questionnaire), and quality of life (12-Item Short-Form Health Survey). Secondary outcomes were painful positions, use of analgesic drugs, and referred pain. Analysis of variance and relative risk were used to analyze the data for the primary and secondary outcome measures, respectively. The number of participants reaching the minimal clinically important difference in the 2 groups for each outcome measure was compared using relative risk. RESULTS: A significant difference in scores on the Roland-Morris Questionnaire (P = .011) and the physical component of the 12-Item Short-Form Health Survey (P = .048), and in the number of participants reaching the minimal clinically important difference for the Roland-Morris Questionnaire (relative risk, 1.79; 95% confidence interval [CI]: 1.05, 3.04) and the secondary outcome of painful positions (relative risk, 1.37; 95% CI: 1.03, 1.83) were found in favor of the experimental treatment. CONCLUSIONS: Trunk balance exercises combined with flexibility exercises were found to be more effective than a combination of strength and flexibility exercises in reducing disability and improving the physical component of quality of life in patients with chronic low back pain. LEVEL OF EVIDENCE: Therapy, level 1b–.

J Orthop Sports Phys Ther 2011;41(8):542-552. Epub 7 June 2011. doi:10.2519/jospt.2011.3413

KEY WORDS: LBP, lumbar spine, stabilization

STUDY DESIGN: Randomized clinical trial. OBJECTIVES: To determine if females with patellofemoral pain syndrome (PFPS) who perform hip strengthening prior to functional exercises demonstrate greater improvements than females who perform quadriceps strengthening prior to the same functional exercises. BACKGROUND: Although PFPS has previously been attributed to quadriceps dysfunction, more recent research has linked this condition to impairment of the hip musculature. Lower extremity strengthening has been deemed an effective intervention. However, research has often examined weight-bearing exercises, making it unclear if increased strength in the hip, quadriceps, or both is beneficial. METHODS: Thirty-three females with PFPS performed either initial hip strengthening (hip group) or initial quadriceps strengthening (quad group) for 4 weeks, prior to 4 weeks of a similar program of functional weight-bearing exercises. Self-reported pain, function, and functional strength were measured. Isometric strength was assessed for hip abductors, external rotators, and knee extensors. A mixed-model analysis of variance was used to determine group differences over time. RESULTS: After 4 weeks, there was less mean ± SD pain in the hip group (2.4 ± 2.0) than in the quad group (4.1 ± 2.5) (P = .035). From baseline to 8 weeks, the hip group demonstrated a 21% increase (P<.001) in hip abductor strength, while that remained unchanged in the quad group. All participants demonstrated improved subjective function (P<.006), objective function (P<.001), and hip external rotator strength (P = .004) from baseline to testing at 8 weeks. CONCLUSION: Both rehabilitation approaches improved function and reduced pain. For patients with PFPS, initial hip strengthening may allow an earlier dissipation of pain than exercises focused on the quadriceps. LEVEL OF EVIDENCE: Therapy, level 2b–.

J Orthop Sports Phys Ther 2011;41(8):560-570. Epub 7 June 2011. doi:10.2519/jospt.2011.3499

KEY WORDS: anterior knee pain, clinical trial, kinetic chain, knee rehabilitation

Figure 7 on page 566 was amended in the September 2011 Erratum, and the article PDF with the Erratum page included is provided here. Please see: September 2011 Erratum

SYNOPSIS: There is a growing trend in the physical therapy profession to use conventional grayscale brightness (B-mode) ultrasound imaging (USI) as a tool to assess the morphological (form and structure) and morphometric (measures of form) characteristics of muscle, and to use these findings to draw conclusions regarding muscle function. This trend is reflected in numerous published investigations. As many physical therapists may lack training in the principles and instrumentation underlying USI use, it is critical that therapists gain a clear understanding of the information that USI can, and cannot, provide about muscle function before employing the technique for either research or clinical applications. Failure to do so may result in the propagation of inaccurate terminology and beliefs. This paper aims to clarify the role that USI has in the assessment of muscle function, first, by briefly reviewing how conventional grayscale B-mode ultrasound images and clips are generated, and second, by summarizing the types of information that these images can provide. It also discusses the various factors that need to be considered when interpreting a dynamic USI assessment of muscle specifically as it relates to the assessment of muscle function.

J Orthop Sports Phys Ther 2011;41(8):572-580, Epub 7 June 2011. doi:10.2519/jospt.2011.3682

KEY WORDS: morphology, morphometry, sonography

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To investigate the relationship between quadriceps force steadiness and knee adduction moment during walking in patients with knee osteoarthritis (OA). BACKGROUND: Studies have shown that quadriceps force steadiness is impaired in patients with knee OA. Furthermore, patients with knee OA, compared to healthy controls, have also demonstrated a significantly higher external knee adduction moment during walking. However, no studies have examined the relationship between quadriceps force steadiness and the peak knee adduction moment during walking in this population. METHODS: Forty-one patients with knee OA (34 females and 7 males) were included in the study. Submaximal isometric quadriceps force steadiness was measured during a force target-tracking task. Peak knee adduction moments during ambulation were measured using a 3-dimensional gait analysis system, and knee pain was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) pain subscale and a visual analog scale. RESULTS: Regression analyses showed that quadriceps force steadiness did not predict the peak knee adduction moment (adjusted R² = 0.05, P = .41). Inclusion of covariates did not change the outcome. CONCLUSION: No statistically significant association between submaximal isometric quadriceps force steadiness and peak knee external adduction moments during walking was found. It could be speculated that submaximal isometric quadriceps muscle force steadiness and knee joint loads during walking represent 2 distinctive pathways and may have independent influences on knee OA pathogenesis.

J Orthop Sports Phys Ther 2011;41(8):592-599, Epub 12 July 2011. doi:10.2519/jospt.2011.3481

KEY WORDS: gait, knee OA, motor control, tibiofemoral joint

STUDY DESIGN: Controlled laboratory study using a cross-sectional design. OBJECTIVES: To analyze lower extremity kinematics during takeoff of a “saut de chat” (leap) in dancers with and without a history of Achilles tendinopathy (AT). We hypothesized that dancers with AT would demonstrate different kinematic strategies compared to dancers without pathology, and that these differences would be prominent in the transverse and frontal planes. BACKGROUND: AT is a common injury experienced by dancers. Dance leaps such as the saut de chat place a large demand on the Achilles tendon. METHODS: Sixteen female dancers with and without a history of AT (mean ± SD age, 18.8 ± 1.2 years) participated. Three-dimensional kinematics at the hip, knee, and ankle were quantified for the takeoff of the saut de chat, using a motion analysis system. A force platform was used to determine braking and push-off phases of takeoff. Peak sagittal, frontal, and transverse plane joint positions during the braking and push-off phases of the takeoff were examined statistically. Independent samples t tests were used to evaluate group differences (α = .05). RESULTS: The dancers in the tendinopathy group demonstrated significantly higher peak hip adduction during the braking phase of takeoff (mean ± SD, 13.5° ± 6.1° versus 7.7° ± 4.2°; P = .046). During the push-off phase, dancers with AT demonstrated significantly more internal rotation at the knee (13.2° ± 5.2° versus 6.9° ± 4.9°; P = .024). CONCLUSION: Dancers with AT demonstrate increased peak transverse and frontal plane kinematics when performing the takeoff of a saut de chat. These larger displacements may be either causative or compensatory factors in the development of AT.

J Orthop Sports Phys Ther 2011;41(8):606-613, Epub 12 July 2011. doi:10.2519/jospt.2011.3580

KEY WORDS: ankle, biomechanics, dance, hip, leaps, saut de chat, tendon

The patient was an 18-year-old male military trainee who presented to a physical therapist with a chief complaint of right ankle pain following a combined plantar flexion-eversion ankle injury 3 days earlier. Based on the suspicion of a fracture, ankle radiographs were ordered by the physical therapist. On the lateral radiographic view, a longitudinal nondisplaced fracture of the posterior aspect of the distal tibia was appreciated.

J Orthop Sports Phys Ther 2011;41(8):615. doi:10.2519/jospt.2011.0417

KEY WORDS: ankle, radiography, tibia

Correction to an article published in May 2011 of the Journal of Orthopaedic & Sports Physical Therapy:

• Briem K, Eythörsdöttir H, Magnúsdóttir RG, Pálmarsson R, Rúnarsdöttir T, Sveinsson T. Effects of Kinesio Tape compared with nonelastic sports tape and the untaped ankle during a sudden inversion perturbation in male athletes. J Orthop Sports Phys Ther 2011;41(5):328-335. doi:10.2519/jospt.2011.3501

J Orthop Sports Phys Ther 2011;41(8):621.