December 2006 Volume 36, No. 12

JOSPT: A Team Effort

The Editor-in-Chief thanks the many dedicated and thoughtful individuals who contributed to the success of the Journal in 2006: the authors of manuscripts, guest editorials, and book reviews; manuscript reviewers, editorial review board members, and associate editors. Journal review time has steadily improved over the past 2 years. The review time for new manuscript submissions averaged 52 days (median 50 days) in 2006, and for revised manuscripts, 30 days (median 27 days). This demonstrates excellent performance by the reviewers and the editorial board members.

J Orthop Sports Phys Ther. 36(12):899-902. doi:10.2519/jospt.2006.0113

A Comparison of Serratus Anterior Muscle Activation During a Wall Slide Exercise and Other Traditional Exercises

Mary Kate McDonnell, Dustin H. Hardwick, Justin A. Beebe, Catherine E. Lang

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

Star Excursion Balance Test as a Predictor of Lower Extremity Injury in High School Basketball Players

Phillip J. Plisky, Mitchell J. Rauh, Thomas W. Kaminski, Frank B. Underwood
Study Design: Prospective cohort. Objective: To determine if Star Excursion Balance Test (SEBT) reach distance was associated with risk of lower extremity injury among high school basketball players. Background: Although balance has been proposed as a risk factor for sports-related injury, few researchers have used a dynamic balance test to examine this relationship. Methods and Measures: Prior to the 2004 basketball season, the anterior, posteromedial, and posterolateral SEBT reach distances and limb lengths of 235 high school basketball players were measured bilaterally. The Athletic Health Care System Daily Injury Report was used to document time loss injuries. After normalizing for lower limb length, each reach distance, right/left reach distance difference, and composite reach distance were examined using odds ratio and logistic regression analyses. Results: The reliability of the SEBT components ranged from 0.82 to 0.87 (ICC_3,1) and was 0.99 for the measurement of limb length. Logistic regression models indicated that players with an anterior right/left reach distance difference greater than 4 cm were 2.5 times more likely to sustain a lower extremity injury (P<.05). Girls with a composite reach distance less than 94.0% of their limb length were 6.5 times more likely to have a lower extremity injury (P<.05). Conclusions: We found components of the SEBT to be reliable and predictive measures of lower extremity injury in high school basketball players. Our results suggest that the SEBT can be incorporated into preparticipation physical examinations to identify basketball players who are at increased risk for injury.

J Orthop Sports Phys Ther. 2006; 36(12):911-919. doi:10.2519/jospt.2006.2244

Key Words: female athlete, neuromuscular control, postural stability

The Use of Real-Time Ultrasound Imaging for Biofeedback of Lumbar Multifidus Muscle Contraction in Healthy Subjects

Khai Van, Julie A. Hides, Carolyn A. Richardson

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

Scapular Angular Positioning at End Range Internal Rotation in Cases of Glenohumeral Internal Rotation Deficit

Paula M. Ludewig, Michael R. Borich, Jolene M. Bright, David J. Lorello, Cort J. Cieminski, Terry Buisman
Study Design: Controlled laboratory study. Objectives: Investigate the relationship between glenohumeral internal rotation range-of-motion deficit and 3-dimensional scapular angular positioning during active arm movements in participants with recent participation in overhead sports activity. Background: Subacromial impingement is one of the most common shoulder pathologies and is multifactorial in etiology. Posterior glenohumeral joint capsule tightness has been theorized to contribute to one potential causal factor: abnormal scapular positioning. Methods and Measures: Twenty-three subjects, who had participated in competitive sports involving overhead activity within the last 5 years, were categorized into 2 groups based on the degree of glenohumeral internal rotation deficit (20% deficit threshold). Scapular angular positioning of subjects performing shoulder internal rotation from 90° flexion and abduction shoulder positions was evaluated using 3-dimensional electromagnetic surface tracking. Additional sensors monitored trunk and humeral motion. Scapular position data at end range glenohumeral internal rotation, along with glenohumeral internal rotation range of motion measurements, were used to analyze the relationship between glenohumeral internal rotation deficit and scapular position using 2-way ANOVA and regression analyses. Results: The internal rotation deficit group had significantly greater scapular anterior tilt (9.2° difference, P = .04) across positions, as compared to the control group. Regression analysis demonstrated a significant association between glenohumeral internal rotation deficit and scapular position (tilting) during flexed internal rotation (r² = 0.37, P = .03) and for scapular position (anterior tilting and upward rotation) during abducted internal rotation (r² = 0.35, P = .036). Conclusions: These findings demonstrate a significant relationship between glenohumeral internal rotation deficit and abnormal scapular positioning, particularly increased anterior tilt. This relationship identifies a possible mechanism for development of excessive scapular anterior tilt.

J Orthop Sports Phys Ther. 2006; 36(12):926- 934. doi:10.2519/jospt.2006.2241

Key Words: biomechanics, rotator cuff, scapula, shoulder

Knee Joint Stiffness in Individuals With and Without Knee Osteoarthritis: A Preliminary Study

Carol A. Oatis, Edward F. Wolff, Sandra K. Lennon
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

Comparison of Different Structural Foot Types for Measures of Standing Postural Control

Liang-Ching Tsai, Bing Yu, Vicki S. Mercer, Michael T. Gross
Study Design: Matched group comparison of 3 subject groups with 3 different foot structures for force plate and clinical measures of postural control. Objectives: To determine if subjects with different weight-bearing foot structure would demonstrate differences in static standing postural control, and to determine the reliability of study procedures. Background: Weight-bearing foot structure may influence postural control either because of a decreased base of support (supinated foot structure) or because of passive instability of the joints of the foot (pronated foot structure). Methods and Measures: Young adults were categorized based on weight-bearing foot structure into neutral, pronated, or supinated groups (15 subjects per group). Postural control in single-limb stance with eyes closed was assessed using force plate measures and by measuring duration of single-limb stance on a firm floor and on a balance pad. Force plate measures were normalized center-of-pressure average speed, and standard deviation and maximum displacement in the anterior-posterior and medial-lateral directions. Results: Individuals in the supinated group had significantly greater center-of-pressure average speed, greater maximum displacement in the anterior-posterior direction, and greater SD and maximum displacement in the medial-lateral direction than individuals in the neutral group. The individuals in the pronated group had significantly greater SD and maximum displacement in the anterior-posterior direction, used more trials to complete force plate testing, and had shorter single-limb stance duration than those in the neutral group. Conclusion: Individuals with pronated feet or supinated feet have poorer postural control than individuals with neutral feet, but perhaps through different mechanisms.

J Orthop Sports Phys Ther. 2006; 36(12):942-953. doi:10.2519/jospt.2006.2336

Key Words: balance, feet, pronation, supination

Sagittal Plane Knee Motion in the ACL-Deficient Knee During Body Weight Shift Exercises on Different Support Surfaces

Joanna Kvist
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

Letters to the Editor-in-Chief

Michael T. Cibulka, Philip Paul Tygiel, Anthony Delitto

Letters to the Editor-in-Chief published in the December 2006 issue of the Journal.

J Orthop Sports Phys Ther. 2006;36(12):963-967. doi:10.2519/jospt.2006.0202

2006 Author Index

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.