Background: Pectoralis minor tightness is associated with reduced glenohumeral internal rotation range of motion (ROM) and scapular anterior tilt alignment. However, the synergistic effects of the pectoralis minor stretching exercise and scapular posterior tilt strategy on glenohumeral internal rotation ROM and pectoralis minor length remain unexplored.
Objectives: This study examined the effects of doorway stretching with scapular posterior tilt on pectoralis minor length, scapular alignment, and glenohumeral internal rotation ROM.
Design: A case series study.
Methods: Fifteen adults with pectoralis minor tightness performed doorway stretching with scapular posterior tilt. Pectoralis minor length, acromion–table distance, and glenohumeral internal rotation ROM were measured before and immediately after stretching. The pectoralis minor length was calculated using the pectoralis minor index. The measured variables were analyzed using a paired t-test.
Results: While the pectoralis minor index and glenohumeral internal rotation ROM significantly increased, the acromion–table distance markedly decreased after doorway stretching with scapular posterior tilt (P<.05).
Conclusion: Based on the present findings, doorway stretching with scapular posterior tilt could be an effective exercise for increasing glenohumeral internal rotation ROM and pectoralis minor length.
Background: Although it has been reported that both self-myofascial release (SMR) with foam rolling (FR) and active static hamstring stretching (e.g., jackknife stretching) are effective in improving hamstring flexibility, no study has compared the effects of these exercises.
Objectives: To compare the effects of SMR with FR and jack-knife stretching on hamstring flexibility.
Design: A Randomized controlled trial.
Methods: Subjects with hamstring tightness were divided into the SMR with the FR group (n=12) and the jack-knife stretching group (n=12). Subjects groups performed SMR with FR or jack-knife stretching according to group assignment. To identify changes in hamstring flexibility, the finger-to-floor distance (FFD) test, active knee extension (AKE) test, and passive straight leg raising (PSLR) test were performed at pre- and post-exercise.
Results: Significant increases occurred in knee extension angle during the AKE test and hip flexion angle during the PSLR test after exercise in both groups (P<.001). Additionally, FFD and anterior pelvic tilt during the FFD test significantly increased (P<.001); however, we observed no significant interaction and main effects for the groups (P>.05).
Conclusion: Both SMR with FR and jack-knife stretching are effective in improving hamstring flexibility in subjects with hamstring tightness.
Background: Although the scapular posterior tilt movement could facilitate the lower trapezius (LT) muscle activity, no study identified the effects of the scapular posterior tilt movement on the selective activation of the LT muscle during prone shoulder extension.
Objectives: To examine the influences of additional scapular posterior tilt on electromyography (EMG) of the upper trapezius (UT) and the LT muscles during prone shoulder extension.
Design: Cross-sectional study.
Methods: There were 15 asymptomatic male participants in this study who performed prone shoulder extension with and without scapular posterior tilt movements. For the scapular posterior tilt movements, participants performed visual biofeedback training for scapular movement using motion sensor. During the exercises, the EMG activity of the UT and LT was recorded using surface EMG system.
Results: The EMG activity of the LT significantly increased during prone shoulder extension with scapular posterior tilt compared to that of general prone shoulder extension, whereas that of the UT was not significantly different between the two exercises. Moreover, scapular posterior tilt application significantly decreased UT/LT muscle activity ratio.
Conclusion: Scapular posterior tilt movement may be emphasized during exercise when facilitating LT muscle activation.
Background: Shoulder horizontal abduction in the prone position (SHAP) has been reported as an effective exercise to strengthen the lower trapezius. However, the effects of pre-emptive scapular posterior tilt on scapular muscle activity and scapulohumeral movements during SHAP have not been examined.
Objectives: To examine the effect of the addition of scapular posterior tilt on muscle activity of the trapezius and posterior deltoid, and scapular posterior tilt and shoulder horizontal abduction, during SHAP.
Design: Cross-sectional study.
Methods: Fifteen healthy male subjects performed two types of SHAP: general and modified SHAP (SHAP combined with pre-emptive scapular posterior tilt). To perform modified SHAP, pre-emptive scapular posterior tilt training was performed prior to the modified SHAP. Muscle activity of the middle and lower trapezius and posterior deltoid, and the amount of scapular posterior tilt and shoulder horizontal abduction, were measured during two types of SHAP.
Results: Muscle activity of the lower trapezius and scapular posterior tilt was significantly increased during the modified SHAP, while muscle activity of the posterior deltoid and the amount of shoulder horizontal abduction were significantly decreased. However, the middle trapezius muscle activity did not change during the modified SHAP.
Conclusion: The SHAP with pre-emptive scapular posterior tilt can be useful to strengthen the lower trapezius.
Background: Static hamstring stretching exercises have been widely used to improve flexibility of the hamstring muscles. However, few studies have examined the influence of standing static hamstring stretching (e.g., jack-knife stretching) on movements of the lumbopelvic–hip complex. Objectives: To examine the short-term effects of jack-knife stretching on movements of the lumbopelvic–hip complex.
Design: Case series.
Methods: Fourteen participants with hamstring tightness (8 male, 6 female) were recruited. Participants performed jack-knife stretching for 150 s. Before and after stretching, participants performed the finger-to-floor distance (FFD), sit and reach (SRT), active knee extension (AKE), passive straight leg raising (PSLA), and active straight leg raising (ASLR) tests as well as pelvic tilt while standing to identify the effects of stretching.
Results: There were significant improvements in the FFD, SRT, AKE, PSLA, and ASLR tests after stretching. However, pelvic tilt angle while standing did not significantly change.
Conclusion: Jack-knife stretching can be a useful exercise to improve flexibility of the hamstring muscles, but not pelvic alignment while standing.
Background: Lower trapezius muscle function is important for the prevention and treatment of shoulder injuries. However, scapular posterior tilt movement has been overlooked in lower trapezius strengthening exercise programs.
Objective: To examine the effects of prone arm lifting with scapular posterior tilt (PALSPT) on trapezius muscles.
Design: Crossover study
Methods: 17 healthy males were recruited for participation in this study. Participants performed backward rocking diagonal arm lifting (BRDAL) and PALSPT. To train participants in scapular posterior tilt movements for PALSPT, visual biofeedback of scapular movements was provided using a motion sensor. Electromyography (EMG) activities of the middle and lower trapezius were recorded using a surface EMG system. Differences in middle and lower trapezius muscle activity between BRDAL and PALSPT exercises were analyzed.
Results: Lower trapezius muscle activity was significantly greater during PALSPT than during BRDAL (p=.006). Although greater EMG activity was observed in the middle trapezius during PALSPT than during BRDAL, this difference was not significant (p=.055).
Conclusions: The results of the present study indicate that scapular posterior tilt movements must be considered in lower trapezius muscle strengthening programs.
Background: Ipsilateral pelvic elevation has been reported as a common compensatory movement during side-lying hip abduction. It has been reported that pelvic elevation inhibits sufficient contraction of gluteus medius. However, few studies have identified the effects of controlled pelvic elevation on the trunk and hip muscles.
Objective: To examine the effects of controlled pelvic elevation using visual biofeedback on the muscle activity of the trunk and hip muscles.
Design: Crossover study.
Methods: Twelve healthy males performed side-lying hip abduction exercises with and without visual biofeedback for pelvic elevation. Electromyography (EMG) activities of the gluteus medius, quadratus lumborum, and multifidus were analyzed using a wireless EMG system while the ipsilateral pelvic elevation angle was measured using a motion sensor during side-lying hip abduction exercises.
Results: EMG activities of the gluteus medius (p = .002), quadratus lumborum (p = .022), and multifidus (p = .020) were significantly increased and ipsilateral pelvic elevation was significantly decreased (p = .001) during side-lying hip abduction with visual biofeedback compared to without visual biofeedback.
Conclusions: The results of this study suggest that the application of biofeedback for pelvic motion could improve the trunk and hip muscle activation pattern and decrease compensatory pelvic motion during side-lying hip abduction exercise.