[Purpose] This study aimed to clarify the activation patterns of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) during scapular girdle flexion–extension and to elucidate the differences between the elevated (shoulder flexion 90°) and dependent (shoulder flexion 0°) arm positions. [Participants and Methods] Twenty-four healthy young males performed repetitive scapular flexion–extension at 1 Hz in both the elevated and dependent arm positions. Surface electromyography was used to record muscle activity, and the maximum amplitude and peak timing were calculated and compared. [Results] The maximum muscle activities of UT, LT and SA were greater in the elevated position. In addition, the peak timing of LT and SA occurred earlier in the elevated position. [Conclusion] The results show that muscle activities and activation timings of the periscapular muscles vary with arm position. Position-specific evaluation may be useful for functional assessment of scapular girdle performance depending on participant condition and clinical purpose.

[Purpose] We examined the relationship between the narrowing rate of the acromio-humeral interval and physical function. [Participants and Methods] The relationships between spinal and scapular alignment, posterior shoulder tightness, and rotator cuff muscle strength in relation to the rate of narrowing of acromio-humeral interval, joint angle, and acromio-humeral interval were examined in 31 healthy university students considering gravity loading by limb position. [Results] The acromio-humeral interval of 45° shoulder abduction with gravity loading was significantly lower than those of the gravity-loaded and non-gravity-loaded shoulder abduction positions. The rate of narrowing of the acromio-humeral interval was significantly positively correlated with posterior shoulder tightness and significantly negatively correlated with the strength of the subscapularis muscle. [Conclusion] These results suggest the need to evaluate patients with subacromial impingement syndrome from multiple perspectives, including the narrowing rate of the acromio-humeral interval, posterior shoulder tightness, and subscapularis muscle strength.

[Purpose] This study investigated the associations between preoperative thoracic spine and scapular alignment and postoperative pain in patients with rotator cuff tears. [Participants and Methods] The study included 32 patients scheduled for arthroscopic rotator cuff repair. The study variables included basic information, thoracic kyphosis angle, scapular alignment, resting pain, nighttime pain, and shoulder elevation pain assessed using a Visual Analogue Scale (VAS) at baseline and at 12 weeks postoperatively. We examined the temporal changes in pain intensity from baseline to 12 weeks postoperatively, and the association between preoperative alignment related to the VAS for shoulder elevation pain at 12 weeks postoperatively. [Results] The VAS for shoulder elevation pain was significantly lower at 12 weeks postoperatively compared to preoperatively. The preoperative factor associated with shoulder elevation pain at 12 weeks postoperatively was thoracic kyphosis angle. [Conclusion] Postoperative pain was associated with an increased preoperative thoracic kyphosis angle.

[Purpose] The purpose of this study was to clarify the relationships between the Functional Reach Test (FRT) and the modified Functional Reach Test under restricted hip joint mobility (modified FRT), and the forward displacement of the center of pressure (COP-A), as well as to examine the reliability and validity of both tests. [Participants and Methods] The participants were 22 healthy adults without motor disorders. The evaluation items were the standard FRT and a modified FRT performed with the hip joint degree of freedom restricted by placing an adapter table against the buttocks. Under both test conditions, the reach distance (FR distance) and COP-A were measured. [Results] Compared to the standard FRT, the modified FRT demonstrated high reliability, with an intraclass correlation coefficient of 0.97 across three trials. In addition, a strong correlation (r=0.73) was observed with COP-A. [Conclusion] The modified FRT showed high reliability and validity of measurement. These findings suggest that the modified FRT is useful as an objective index for quantitatively evaluating the balance ability of healthy individuals.

[Purpose] This study aimed to clarify the relationship between toileting independence and physical function, including the Index of Postural Stability (IPS), in hemiplegic stroke patients during the recovery phase, and to determine a cutoff value for predicting toileting independence. [Participants and Methods] We retrospectively analyzed the data of 178 hemiplegic stroke patients admitted to a convalescent rehabilitation ward. [Results] Significant differences were observed between the toileting-independent and non-independent groups in age, IPS, Berg Balance Scale, Mini Mental State Examination (MMSE), and Stroke Impairment Assessment Set-lower extremity. Logistic regression identified IPS and MMSE as significant predictors, and receiver operating characteristic analysis indicated a cutoff value of 1.01 for IPS. [Conclusion] IPS may serve as a useful indicator for evaluating toileting independence in hemiplegic stroke patients during the recovery phase.

[Purpose] To clarify the relationship between the per step increase and decrease of the knee adduction moment (KAM) and knee flexion moment (KFM), the lever arm (LA) and ground reaction force (GRF). [Participants and Methods] Eleven healthy young women performed 20 trials of free gait measured by a three-dimensional motion analysis system and force plate. [Results] KAM and KFM showed a strong correlation with LA, while exhibiting a moderate to weak correlation with GRF. [Conclusion] The results reveal that the step-by-step increase and decrease in KAM and KFM in healthy young women is strongly influenced by LA.