In March, the Journal of Orthopaedic & Sports Physical Therapy moved to a new web platform with the goal of taking greater advantage of current technology to better meet the needs of individual and institutional subscribers and visitors to www.jospt.org. This editorial offers a guide to the Journal's new website, with frequently asked questions and answers.

J Orthop Sports Phys Ther. 2007;37(5):220-222. doi:10.2519/jospt.2007.0105

STUDY DESIGN: Randomized controlled trial with repeated measures. OBJECTIVES: To determine the effect of trunk stability training on vertical takeoff velocity. BACKGROUND: Trunk stability training is commonly used in sports training programs; however, the effects of stability training on performance enhancement are not known. Trunk stability training may provide a more stable pelvis and spine from which the leg muscles can generate action, may better link the upper body to the lower body, or may enhance leg muscle activation, thus promoting optimal force production during sporting activities such as a vertical jump. METHODS AND MEASURES: Fifty-five athletes were randomly assigned to 1 of 4 training groups: trunk stability (TS), leg strength (LS), trunk stability and leg strength (TL), and control (CO). Subjects were tested 3 times: at pretraining, after 3 weeks of training, and after 9 weeks of training. A repeated-measures analysis of covariance (ANCOVA) was used to examine differences among groups for vertical takeoff velocity measured indirectly using a force plate. Pretraining takeoff velocity and body mass were used as covariates. RESULTS: After 3 and 9 weeks, the training groups were not different from each other. After 9 weeks of training, all 3 training groups had a greater takeoff velocity than the control group (P‹.05). After 3 weeks of training, only the TS group had a greater takeoff velocity than the control group (P‹.05). Only the TL group increased significantly in vertical takeoff velocity between the third- and ninth-week testing periods (P‹.05). CONCLUSIONS: Nine weeks of trunk stability training was similarly effective in enhancing vertical takeoff velocity as leg strength training or the combination of trunk stability and leg strength training.

J Orthop Sports Phys Ther. 2007;37(5):223-231; published online 15 March 2007. doi:10.2519/jospt.2007.2331

KEY WORDS: athletic performance, core stability, neural control, vertical jump

STUDY DESIGN: Cross-sectional. OBJECTIVES: To investigate whether females seeking physical therapy treatment for unilateral patellofemoral pain syndrome (PFPS) exhibit deficiencies in hip strength compared to a control group. BACKGROUND: Decreased hip strength may be associated with poor control of lower extremity motion during weight-bearing activities, leading to abnormal patellofemoral motions and pain. Previous studies exploring the presence of hip strength impairments in subjects with PFPS have reported conflicting results. METHODS AND MEASURES: Twenty females aged 12-35 years participated in the study. Ten subjects with unilateral PFPS were compared to 10 control subjects with no known knee pathologies. Hip abduction, extension, and external rotation strength were tested using a hand-held dynamometer. A limb symmetry index (LSI) was used to quantify physical performance for all tests. RESULTS: The symptomatic limbs of subjects with PFPS exhibited impairments in hip strength for all variables tested. LSI values in subjects with PFPS (range, 71%-79%) were significantly lower than those in control subjects (range, 93%-101%) (P≤.007). A secondary analysis of data normalized to body mass demonstrated that the symptomatic limbs of subjects with PFPS had 52% less hip extension strength (P‹.001), 27% less hip abduction strength (p=.007), and 30% less hip external rotation strength (P=.004) when compared to the weaker limbs of control subjects. CONCLUSIONS: Females aged 12-35 presenting with unilateral PFPS demonstrate significant impairments in hip strength compared to control subjects when LSI values or body mass normalized values are used to quantify physical performance of the symptomatic limb.

J Orthop Sports Phys Ther. 2007;37(5):232-238; published online 15 March 2007. doi:10.2519/jospt.2007.2439

KEY WORDS: anterior knee pain, hip abduction, hip extension, hip external rotation, limb symmetry index

STUDY DESIGN: A case-control study, with single observation. OBJECTIVES: To compare the onset timing and activation of the vastus medialis oblique (VMO) and vastus lateralis (VL) between subjects with and without patellofemoral pain syndrome (PFPS) at various step heights. BACKGROUND: It has been theorized that delayed or reduced VMO activity relative to the VL contributes to lateral patellar tracking and PFPS. However, conflicting evidence exists in the literature regarding this proposed mechanism. The lack of agreement among studies may be attributed to inconsistent knee flexion angles used in previous studies. METHODS AND MEASURES: Twenty subjects with PFPS (mean ± SD age, 29.5 ± 10 yrs) and 20 control subjeccts (mean ± SD age, 25.4 ± 3.1 yrs) ascended 5 different step heights, while knee kinematics and quadriceps EMG data were collected. Knee flexion angle at foot-step contact, VMO-VL onset timing, and VMO/VL activation ratios were analyzed between groups and step heights using 2-factor analyses of variance (ANOVAs) with repeated measures (α = .05). RESULTS: Individuals with PFPS demonstrated 4.7° (P = .038) more knee flexion at foot-step contact than control subjects. Despite greater knee flexion with increased step height (P‹.001), no differences in onset timing or activation magnitude ratio were present between groups or across step heights. However, individuals with PFPS displayed a significantly increased activation duration ratio compared to the control group (P = .043). CONCLUSION: Quadriceps onset timing and activation magnitude during stair ascent was similar between individuals with and without PFPS, regardless of step height. Thus, the results of this study are in agreement with evidence indicating no difference in VMO-VL timing and VMO/VL activation magnitude ratio between individuals with and without PFPS.

J Orthop Sports Phys Ther. 2007;37(5):239-244; published online 15 March 2007. doi:10.2519/jospt.2007.2421

KEY WORDS: activation ratio, anterior knee pain, EMG, onset delay, stair climbing

STUDY DESIGN: Mixed-model, repeated-measures design in a laboratory setting. OBJECTIVES: To examine the differences in hip, knee, and ankle kinematics between a bilateral drop-vertical jump and a single-leg step-down. A secondary purpose was to examine gender differences in kinematics of the tasks. BACKGROUND: Both a drop-vertical jump and step-down task have been used to evaluate lower extremity movement and injury risk. The differences in joint angles between these tasks have not been reported. METHODS AND MEASURES: Three-dimensional joint angles of the hip, knee, and ankle of 19 females and 18 males were evaluated with a high-speed camera system while they performed a bilateral drop-vertical jump and a single-leg step-down. Maximum joint angles were compared between tasks and genders using ANOVA models. RESULTS: When averaged across both genders, the step-down produced greater rearfoot eversion (12° compared to 8°) (P‹.0005), and hip adduction (16° compared to 1°) (P=.03) than the drop-vertical jump. Females had greater hip internal rotation in the step-down than in the drop-vertical jump (5° compared to 2°) (P=.02). When averaged across both tasks, females had greater knee abduction than males in both tasks (4° compared to 0°) (P‹.0005). CONCLUSIONS: The unilateral step-down task produced greater motion in the frontal and transverse planes at the ankle and hip, and would be appropriate in evaluating control of the hip during movement. The bilateral drop-vertical jump produced greater knee abduction in both genders, and may be appropriate for evaluating excessive knee abduction as a risk factor for non-contact anterior cruciate ligament injury, for example. The 2 tasks appear to challenge the neuromuscular system in different manners, and both should continue to be used in the investigation of injury risk.

J Orthop Sports Phys Ther. 2007;37(5):245-252; published online 15 March 2007. doi:10.2519/jospt.2007.2202

KEY WORDS: ACL, biomechanics, gender, hip, knee

When choos­ing between conservative/nonoperative versus surgical intervention, the extent of subchondral bone exposed and the time over which the arthritis has developed are factors that should be consid­ered. The role and effectiveness of conservative treatment, such as medication, patient education, shoe modification, bracing, stretching, mobiliza­tion, strengthening, and symptom management, need to be further determined. Surgical proce­dures for posttraumatic ankle arthritis can include distraction arthroplasty, arthrodesis, or total ankle arthroplasty.

Unlike the relatively new procedure of distraction arthroplasty, the outcomes for arthrod­esis have been well defined. Arthrodesis generally has a good outcome, but its limitations have been recognized. These limitations include the extended time required to achieve fusion, potential for non­union, arthritis developing in adjacent joints, leg length discrepancy, malalignment, chronic edema, symptoms due to the hardware, stress fractures, and continued pain. While first generation total an­kle arthroplasty led to poor results, advancements in prosthetic design and surgical technique have revived optimism regarding total ankle arthroplasty as an alternative to arthrodesis. The key for the fu­ture of total ankle arthroplasty may not be related to the development of newer ankle components but rather in refining the criteria to determine who would best benefit from joint replacement versus fusion.

J Orthop Sports Phys Ther. 2007;37(5):253-259. doi:10.2519/jospt.2007.2404

KEY WORDS: arthrodesis, arthroplasty, joint fusion, joint replacement

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: To quantify phase duration and lower extremity muscle activation and alignment during the most common types of soccer kick - the instep kick and side-foot kick. A second purpose was to test the hypotheses that different patterns of lower extremity muscle activation occur between the 2 types of kicks and between the kicking limb compared to the support limb. BACKGROUND: Soccer players are at risk for lower extremity injury, especially at the knee. Kicking the soccer ball is an essential, common, and distinctive part of a soccer player's activity that plays a role in soccer player injury. Regaining the ability to kick is also essential for soccer athletes to return to play after injury. METHODS: Thirteen male soccer players underwent video motion analysis and eletromyography (EMG) of 7 muscles in both the kicking and supporting lower extremity (iliacus, gluteus maximus, gluteus medius, vastus lateralis, vastus medialis, hamstrings, gastrocnemius) and 2 additional muscles in the kicking limb only (hip adductors, tibialis anterior). Five instep and 5 side-foot kicks were recorded for each player. Analysis-of-variance models were used to compare EMG activity between type of kicks and between the kicking and nonkicking lower extremity. RESULTS: Five phases of kicking were identified: (1) preparation, (2) backswing, (3) limb cocking, (4) acceleration, and (5) follow-through. Comparing the kicking limb between the 2 types of kick, significant interaction effects were identified for the hamstrings (P = .02) and the tibialis anterior (P‹.01). Greater activation of the kicking limb iliacus (P‹.01), gastrocnemius (P‹.01), vastus medialis (P = .016), and hip adductors (P‹.01) occurred during the instep kick. Significant differences were seen between the kicking limb and the support limb for all muscles during both types of kick. CONCLUSIONS: Certain lower extremity muscle groups face different demands during the soccer instep kick compared to the soccer side-foot kick. Similarly, the support limb muscles face different demands than the kicking limb during both kicks. Better definition of lower extremity function during kicking provides a basis for improved insight into soccer player performance, injury prevention, and rehabilitation.

J Orthop Sports Phys Ther. 2007;37(5):260-268; published online 15 March 2007. doi:10.2519/jospt.2007.2255

KEY WORDS: football, kicking, motion analysis

STUDY DESIGN: A controlled, randomized prospective study. OBJECTIVE: To assess the changes in paratendon microcirculation after 12 weeks of daily painful eccentric training in individuals with chronic Achilles tendinopathy. BACKGROUND: Changes in tendon and paratendon microcirculation are evident in insertional and midportion Achilles tendinopathy. Whether the paratendon is involved in eccentric training response is not known. METHODS: Twenty patients with chronic Achilles tendinopathy were recruited for a prospective, controlled trial using eccentric exercise. A laser Doppler system assessed capillar blood flow (flow), tissue oxygen saturation (SO₂), and postcapillary venous filling pressure (rHB) at 8 paratendon locations at depths of 2 and 8mm. RESULTS: Pain in the eccentric-training group was reduced by 48% (from a mean of 4.1 ± 2.9 to 2.1 ± 2.2, P‹.05). Deep paratendon blood flow decreased at the midportion paratendon location (P‹.05). Superficial blood flow at the medial distal midportion position (by 31%, P = .008) and the lateral proximal midportion location (by 45%, P = .016) were significantly decreased postintervention. No significant change of superficial or deep paratendon oxygenation was found after intervention as compared to baseline. Deep paratendon postcapillary venous filling pressures were significantly reduced following eccentric training (P‹.05). CONCLUSION: An eccentric-training program performed daily over 12 weeks reduced the increased paratendinous capillary blood flow in Achilles tendinopathy by as much as 45% and decreased pain level on a visual analog scale. Local paratendon oxygenation was preserved while paratendinous postcapillary venous filling pressures were reduced after 12 weeks of eccentric training, which appears to be beneficial from the perspective of microcirculation.

J Orthop Sports Phys Ther. 2007;37(5):269-276; published online 15 March 2007. doi:10.2519/jospt.2007.2296

KEY WORDS: tendon, microcirculation, training, rehabilitation, ultrasound

The JOSPT offers invited reviews of current titles. The May 2007 column includes 12 reviews of the following books: Surgical Techniques for the Knee; Cartilage Injury in the Athlete; Therapeutic Modalities for Musculoskeletal Injuries, Second Edition; Posterolateral Knee Injuries: Anatomy, Evaluation, and Treatment; Low Back Syndromes: Integrated Clinical Management; Rehabilitation of the Spine: A Practitioner's Manual, Second Edition; Orthotics and Prosthetics in Rehabilitation, Second Edition; Whiplash-Associated Diseases; Sports Injuries of the Knee: Surgical Approaches; Imaging Strategies for the Knee; Shoulder Rehabilitation: Non-Operative Treatment; and Pilates for Fragile Backs.

J Orthop Sports Phys Ther. 2007;37(5):277-285.