Study Design: Single-group repeated-measures design. Objectives: To investigate the ability of the wall slide exercise to activate the serratus anterior muscle (SA) at and above 90° of humeral elevation. Background: Strengthening of the SA is a critical component of rehabilitation for patients with shoulder impingement syndromes. Traditional SA exercises have included scapular protraction exercises such as the push-up plus. These exercises promote activation of the SA near 90° of humeral elevation, but not in positions above 90° where patients typically experience pain. Methods and Measures: Twenty healthy subjects were studied performing 3 exercises: (1) wall slide, (2) plus phase of a wall push-up plus, and (3) scapular plane shoulder elevation. Three-dimensional position of the thorax, scapula, and humerus and muscle activity from the SA, upper and lower trapezius, and latissimus dorsi were recorded. The magnitudes of activation for each muscle at 90°, 120°, and 140° of humeral elevation were quantified from EMG records. Repeated-measures analyses of variance were used to determine the degree to which the different exercises activated the SA at the 3 humeral positions. Results: The intensity of SA activity was not significantly different between the 3 exercises at 90° of humeral elevation (P = .40). For the wall slide and scapular plane shoulder elevation exercises, SA activity increased with increasing humeral elevation angle (P = .001), with no significant differences between the 2 exercises (P = .36). Conclusion: The wall slide is an effective exercise to activate the SA muscle at and above 90° of shoulder elevation. During this exercise, SA activation is not significantly different from SA activation during the push-up plus and scapular plane shoulder elevation, 2 exercises previously validated in the literature. 

J Orthop Sports Phys Ther. 2006; 36(12):903-910. doi:10.2519/jospt.2006.2306 

Key Words: electromyography, scapula, shoulder

Study Design: Randomized controlled trial. Objective: To determine if the provision of visual biofeedback using real-time ultrasound imaging enhances the ability to activate the multifidus muscle. Background: Increasingly clinicians are using real-time ultrasound as a form of biofeedback when re-educating muscle activation. The effectiveness of this form of biofeedback for the multifidus muscle has not been reported. Methods and Measures: Healthy subjects were randomly divided into groups that received different forms of biofeedback. All subjects received clinical instruction on how to activate the multifidus muscle isometrically prior to testing and verbal feedback regarding the amount of multifidus contraction, which occurred during 10 repetitions (acquisition phase). In addition, 1 group received visual biofeedback (watched the multifidus muscle contract) using real-time ultrasound imaging. All subjects were reassessed a week later (retention phase). Results: Subjects from both groups improved their voluntary contraction of the multifidus muscle in the acquisition phase (P<.001) and the ability to recruit the multifidus muscle differed between groups (P<.05), with subjects in the group that received visual ultrasound biofeedback achieving greater improvements. In addition, the group that received visual ultrasound biofeedback retained their improvement in performance from week 1 to week 2 (P>.90), whereas the performance of the other group decreased (P<.05). Conclusion: Real-time ultrasound imaging can be used to provide visual biofeedback and improve performance and retention in the ability to activate the multifidus muscle in healthy subjects.

J Orthop Sports Phys Ther. 2006; 36(12):920-925. doi:10.2519/jospt.2006.2304

Key Words: lumbar spine, motor learning, sonography, stabilization, trunk exercises

Study Design: Descriptive, case-matched comparison. Objectives: To compare the knee joint stiffness and damping coefficients of individuals with knee osteoarthritis (KOA) to those of age- and gender-matched individuals without KOA. A secondary purpose was to investigate relationships between these coefficients and complaints of stiffness in individuals with KOA. Background: KOA is a leading cause of disability, and stiffness is a common complaint in individuals with KOA. Yet the most common method of assessing knee joint stiffness is through a self-report questionnaire. Methods and Measures: Stiffness and damping coefficients at the knee were calculated in 10 volunteers (mean age ± SD, 64.1 ± 15.5 years) with KOA and compared to coefficients from age- and gender-matched individuals without KOA, collected in a previous study (mean age ± SD, 62.1 ± 13.9 years). Stiffness and damping coefficients were calculated from the angular motion of the knee during a relaxed oscillation. Spearman correlation coefficients were calculated between stiffness and damping coefficients and WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) scores for subjects with KOA. Results: Independent 2-tailed t tests revealed significantly larger damping coefficients (P = .035) among those with KOA (95% CI, 0.10-2.32 Nm s/rad). Spearman rank correlations revealed a significant positive relationship (r = .85, P = .003) between the damping coefficient and the stiffness subscore of the WOMAC. Conclusion: This study offers preliminary data demonstrating the feasibility of measuring stiffness and damping coefficients in individuals with KOA. Additionally, the damping coefficient is increased in people with KOA when compared to age- and gender-matched individuals without KOA. The damping coefficient appears to be associated with the complaints of stiffness reported by the WOMAC.

J Orthop Sports Phys Ther. 2006; 36(12):935-941. doi:10.2519/jospt.2006.2320 

Key Words: arthritis, pendulum test, tibiofemoral joint, WOMAC

Study Design: Experimental design with group comparisons. Objectives: To compare anterior tibial translation and muscle activity among different exercises for early weight-bearing and neuromuscular training in individuals with a unilateral anterior cruciate ligament (ACL) injury and in uninjured controls. Background: The effects of exercise and activity on tibial translation must be taken into consideration during rehabilitation after ACL injury. Methods and Measures: Twelve patients with an ACL-deficient knee and 12 age- and gender-matched controls participated in the study. Sagittal tibial translation and muscle activity were registered during the Lachman test (static translation) and 4 body weight shift exercises (dynamic translation). A Student t test with Bonferroni correction and analysis of variance were used for the statistical analysis. Results: Forward-backward body weight shift exercise resulted in smaller anterior tibial translation compared to body weight shift from side to side. Analysis of EMG activity could not explain this difference in anterior tibial translation. The amount of anterior tibial translation or EMG activity did not change when the exercises were performed on a trampoline compared to a firm surface. Conclusions: Forward-backward weight shifting may be preferable in initial rehabilitation after ACL injury compared to body weight shift from side to side.

J Orthop Sports Phys Ther. 2006; 36(12):954-962. doi:10.2519/jospt.2006.2290 

Key Words: EMG, functional joint stability, knee kinematics, rehabilitation

This index includes all authors and co-authors of manuscripts published in the Journal during 2006.

 J Orthop Sports Phys Ther. 2006;36(12):969-991.