Jiu-Jenq Lin

Effects of weight-bearing versus nonweight-bearing exercise on function, walking speed, and position sense in participants with knee osteoarthritis: a randomized controlled trial

OBJECTIVE To investigate whether weight-bearing (WB) exercise enhances functional capacity to a greater extent than nonweight-bearing (NWB) exercise in participants with knee osteoarthritis. DESIGN Randomized controlled trial. SETTING Kinesiology laboratory. PARTICIPANTS Participants (N=106) were randomly assigned to WB exercise, NWB exercise, or a control group (no exercise). INTERVENTION WB exercise and NWB exercise groups underwent an 8-week knee extension-flexion exercise program. MAIN OUTCOME MEASURES Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scale, walking speed, muscle torque, and knee reposition error were assessed before and after intervention. RESULTS Equally significant improvements were apparent for all outcomes after WB exercise and NWB exercise, except for reposition error, for which improvement was greater in the WB exercise group. In contrast, there were no improvements in the control group. CONCLUSIONS Simple knee flexion and extension exercises (WB and NWB) performed over 8 weeks resulted in significant improvement in the WOMAC function scale and knee strength compared with the control group. NWB exercise alone may be sufficient enough to improve function and muscle strength. The additional benefit of WB exercise was improved position sense, which may enhance complex walking tasks (walking on figure of 8 route and spongy surface).

Mobilization Techniques in Subjects With Frozen Shoulder Syndrome: Randomized Multiple-Treatment Trial

Background and Purpose: The purpose of this study was to compare the use of 3 mobilization techniques—end-range mobilization (ERM), mid-range mobilization (MRM), and mobilization with movement (MWM)—in the management of subjects with frozen shoulder syndrome (FSS). Subjects: Twenty-eight subjects with FSS were recruited. Methods: A multiple-treatment trial on 2 groups (A-B-A-C and A-C-A-B, where A=MRM, B=ERM, and C=MWM) was carried out. The duration of each treatment was 3 weeks, for a total of 12 weeks. Outcome measures included the functional score and shoulder kinematics. Results: Overall, subjects in both groups improved over the 12 weeks. Statistically significant improvements were found in ERM and MWM. Additionally, MWM corrected scapulohumeral rhythm significantly better than ERM did. Discussion and Conclusion: In subjects with FSS, ERM and MWM were more effective than MRM in increasing mobility and functional ability. Movement strategies in terms of scapulohumeral rhythm improved after 3 weeks of MWM.

The effects of scapular taping on electromyographic muscle activity and proprioception feedback in healthy shoulders

We investigated the effects of scapular tape on the electromyographic (EMG) activity of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), anterior deltoid (AD), and shoulder proprioception in 12 healthy shoulders. Participants were blindfolded and required to complete a target end/mid range position with the hand. They performed six trials under two experimental conditions; no tape and therapeutic tape. EMG activity was measured by surface electrodes, and proprioception was measured by the FASTRAK electromagnetic motion tracking system. Two‐way repeated measures ANOVA showed that UT and AD activities decreased 2.65% (p = 0.001), and SA muscular activities increased 1.9% (p = 0.015) in the taping condition. The proprioceptive feedback magnitude was significantly lower in the taping condition than in the no taping condition (11.9°, p < 0.005). Additionally, correlation coefficients were higher than 0.5 between muscle activity and proprioceptive feedback with the taping condition; UT and magnitude in the mid range task (R = 0.516); LT and magnitude in the end range task (R = −0.524); and SA and magnitude in the mid range task (R = −0.576). The results suggest that scapular tape affects the muscle activity of UT, AD, and SA, and that the effects are related to proprioception feedback. These results implicate that the mechanisms by which scapular taping induces effects can be explained by neuromuscular control and proprioceptive feedback factors.

Adaptive patterns of movement during arm elevation test in patients with shoulder impingement syndrome

The purpose of this study was to determine if a distinctive characteristic exists in the pattern of movement (scapular elevation and upward rotation to reduce impingement) and associated muscular activities during arm elevation in subjects with shoulder impingement (SI) that is associated with the severity of the disease. Fourteen subjects (7 amateur athletes and 7 student athletes) with SI and 7 controls performed arm elevation in the scapular plane. Scapular kinematics (upward rotation, elevation, tipping, and scapulohumeral rhythm) and muscular activity [upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and deltoid] were measured by an electromagnetic motion tracking system and surface electromyography, respectively. Subjects with SI had greater elevation of the scapula (11.9 mm, p < 0.005) and less peak scapular posterior tipping (10.6°, p < 0.02) than controls. In more severe subjects (amateur athletes), the elevation and posterior tipping of the scapula were correlated with an increase in the UT (R = −0.818, p = 0.025) and a decrease in SA (R = 0.772, p = 0.040) activity, respectively. Our results identified a characteristic compensatory scapular elevation to reduce impingement during arm elevation in subjects with SI. Assessing scapular elevation during arm elevation may be a useful functional marker for evaluating impingement status and associated muscle function. Additionally, SA and LT muscle strengthening may improve SI.

Trapezius muscle imbalance in individuals suffering from frozen shoulder syndrome

This aim of this study was to characterize upper and lower trapezius muscle activity for patients experiencing frozen shoulder syndrome (FSS) compared to asymptomatic subjects. Fifteen patients suffering from unilateral FSS and 15 asymptomatic subjects voluntarily participated in this study. Data were gathered on electromyographic (EMG) activity obtained from the upper and lower trapezius muscles during maximal static arm elevations at six different testing positions: 60 and 120° of flexion, abduction in the frontal plane, and abduction in the scapular plane. The group with FSS revealed increased upper trapezius EMG activity at the 60° (mean difference=12%, p<0.003) and 120° (mean difference=24%, p<0.004) testing positions, and increased lower trapezius EMG activity at the 120° testing positions (mean difference=6%, p<0.002), compared to asymptomatic subjects. Higher ratios of the upper trapezius to lower trapezius EMG activity were also found in the patient group (p<0.0005) compared to asymptomatic subjects. The results of this study indicate that the increased trapezius muscle activity may contribute to scapular substitution movement in compensation for impaired glenohumeral motion in patients with FSS. The insufficiency of the increased lower trapezius muscle activity should be an important consideration in the rehabilitation of patients experiencing FSS.

Functional activities characteristics of shoulder complex movements: Exploration with a 3-D electromagnetic measurement system.

The high prevalence of shoulder-related dysfunction has focused increased attention on functional activity assessment. This study (1) tested the reliability of three-dimensional shoulder complex movements during four functional tasks representing different levels of task difficulty, (2) characterized the four functional tasks, and (3) examined the relationships between age and shoulder movements. Twenty-five asymptomatic subjects, all veterans aged 30-82, performed the four functional tasks. Good within-session reliability was found (movement pattern: similarity index = 0.81 to 0.97, peak values: intraclass correlation coefficients = 0.88 to 0.99). The raising arm to overhead height task (hard task) placed the greatest demand on scapular motions and humeral elevation (p < 0.005). During the functional tasks, significant correlations existed between age and scapular tipping, humeral elevation, and scapular upward rotation (r = -0.62 to 0.50, p < 0.05). Correlation results indicated that elderly subjects have a greater potential for serratus anterior muscle weakness and shoulder capsule tightness.

Role of the Vastus Medialis Obliquus in Repositioning the Patella: A Dynamic Computed Tomography Study

Background It has been assumed that patellofemoral pain syndrome results from patellar malalignment. The precise role the vastus medialis obliquus plays in mediating the underlying pathologic abnormality is unclear. Hypothesis The morphologic characteristics of the vastus medialis obliquus correlate to patellar malalignment in patients with patellofemoral pain syndrome. Study Design Cross-sectional study; Level of evidence, 3. Methods One hundred twelve patients with patellofemoral pain syndrome were studied. Six sets of computed tomography axial images were assessed in which knee flexion was 0°, 15°, or 30° and the quadriceps muscle either relaxed or contracted. Measurements of serial cross-sectional areas of the vastus medialis obliquus and patellar malalignment were made. Correlation and stepwise regression models between the vastus medialis obliquus variables and patellar malalignment (lateral shift and patellar tilt) were calculated. Statistics were calculated on 4 subgroups depending on patellofemoral malalignment type. Results Significant correlations were found between measures of cross-sectional areas of vastus medialis obliquus and patellar tilt at 0° and 30° of knee flexion. Using a regression model, it was determined that vastus medialis obliquus is predictive of patellar tilt (R 2 = 0.078–0.130). This explanation was most apparent in the subgroup of patients with extreme patellar tilt and lateral shift malalignments (R 2 up to 0.824). Conclusion There are significant correlations between vastus medialis obliquus variables and patellar malalignments in extended knees of patients with patellofemoral pain syndrome. Clinical Relevance Vastus medialis obliquus muscle function is important to consider in the rehabilitation of patients with patellofemoral pain syndrome, especially those with extreme patellar tilt and lateral shift malalignments.

Differences in Sonographic Characteristics of the Vastus Medialis Obliquus Between Patients With Patellofemoral Pain Syndrome and Healthy Adults

Background There is controversy regarding the relationship between patellofemoral pain syndrome (PFPS) and insufficiency of the vastus medialis obliquus (VMO). The conventional clinical practice of VMO strengthening for PFPS has been challenged for lack of evidence. The purpose of this study was to observe the difference in sonographic findings of the VMO between patients with PFPS and healthy adults. Hypothesis The morphological characteristics of the VMO are different between patients with PFPS and healthy adults. Study Design Case-control study; Level of evidence, 3. Methods Fifty-four patients with PFPS and 54 age-, gender-, body height—, and body weight—matched healthy adults as controls were enrolled in the study to measure by sonography the insertion level, fiber angle, and volume of the VMO at its insertional portion to detect differences between patients with PFPS and healthy controls. Results The insertion level, fiber angle, and VMO volume were all significantly smaller in the PFPS group than in the control group (P < .05). Multivariate analysis of variance has revealed a Wilks λ value of .845 and an F value of 5.640 (P = .001). Conclusion There was a significant difference in the 3 VMO measures between patients with PFPS and the healthy controls. Individuals might be predisposed to PFPS by different VMO characteristics, including insertion level and fiber angle. The current study cannot determine whether the observed morphological differences were the results of atrophy in response to pain or if they represent dysplasia that was predisposed to pain development. The clinical manifestations of VMO characteristics should be thoroughly investigated in other populations. Clinical Relevance The function of the VMO is important to consider in the rehabilitation of patients with PFPS.

EMG biofeedback effectiveness to alter muscle activity pattern and scapular kinematics in subjects with and without shoulder impingement

BACKGROUND Muscle imbalance between serratus anterior (SA), upper trapezius (UA), middle trapezius (MT), and lower trapezius (LT) muscles has been observed in subjects with subacromial impingement syndrome (SAIS). OBJECTIVE (1) To investigate the effect of electromyography (EMG) biofeedback training on muscle balance ratios and scapular kinematics in healthy adults and subjects with SAIS. (2) To investigate whether the effects of EMG biofeedback on muscle balance ratios are different between groups. DESIGN Twelve healthy adults and 13 subjects with SAIS were recruited in this study. EMG was used to record the activity of scapular muscles. The ratios (UT/SA, UT/MT, and UT/LT) during exercises with/without EMG biofeedback were calculated. Scapular kinematics were recorded before and after exercises with/without EMG biofeedback. RESULTS For the subjects with SAIS, muscle balance ratios were lower during forward flexion with EMG biofeedback than during exercise only (UT/SA: 70.3-45.2; UT/LT: 124.8-94.6). Additionally, similar results were found during side-lying external rotation (UT/MT: 58.5-36.4). For the scapular upward rotation and tipping in both groups, there were no significant differences with and without EMG biofeedback. CONCLUSION EMG biofeedback improved the scapular muscular balance during training exercises in both groups. Further clinical trials should investigate the long-term effects of EMG biofeedback.

Effectiveness of the end-range mobilization and scapular mobilization approach in a subgroup of subjects with frozen shoulder syndrome: A randomized control trial

Treatment strategies targeting abnormal shoulder kinematics may prevent pathology or if the pathology develops, shorten its duration. We examined the effectiveness of the end-range mobilization/scapular mobilization treatment approach (EMSMTA) in a subgroup of subjects with frozen shoulder syndrome (FSS). Based on the kinematics criteria from a prediction method, 34 subjects with FSS were recruited. Eleven subjects were assigned to the control group, and 23 subjects who met the criteria were randomly assigned to the criteria-control group with a standardized physical therapy program or to the EMSMTA group. Subjects attended treatment sessions twice a week for 8 weeks. Range of motion (ROM), disability score, and shoulder complex kinematics were obtained at the beginning, 4 weeks, and 8 weeks. Subjects in the EMSMTA group experienced greater improvement in outcomes compared with the criteria-control group at 4 weeks (mean difference=0.2 of normalized hand-behind-back reach) and 8 weeks (mean difference=22.4 degrees humeral external rotation, 0.31 of normalized hand-behind-back reach, 7.5 disability, 5 degrees tipping and 0.32 rhythm ratio). Similar improvements were found between the EMSMTA group and control group. The EMSMTA was more effective than a standardized physical therapy program in a subgroup of subjects who fit the criteria from a prediction method.