Background/PurposeAnkle sprains are common and potentially disabling musculoskeletal injuries that often lead to chronic ankle instability (CAI). CAI has been linked to impairments in postural and neuromuscular control; however, inconsistent findings have been reported. Individuals who experience a lateral ankle sprain, but do not develop instability, termed copers, may adapt different neuromuscular control strategies after injury. This study aimed to compare postural control and electromyographic (EMG) activity of hip and ankle muscles during the performance of the Star Excursion Balance Test (SEBT) in subjects with and without CAI.Method48 participants were classified into three groups (16 control, 16 copers, 16 CAI) based on ankle sprain history and Cumberland Ankle Instability Tool score. Outcome measures included normalized reach distance, center of pressure (COP), and integrated EMG activation of gluteus medius (Gmed), gluteus maximus (Gmax), tibialis anterior (TA), and peroneus longus (PL) during each reach direction of SEBT.ResultsCompared to copers and controls, CAI group demonstrated significantly diminished postural control (reach distance and COP measures, p< 0.05) and less EMG activity of TA during the anterior direction (CAI: 33.1% ± 10.1% versus copers: 44.8% ± 12.7% versus controls: 51.7% ± 8.4%, p<0.01) and Gmax in the posterolateral direction (CAI: 25.6% ± 9.4% versus copers: 37.5% ± 13.8% versus controls: 40.2% ± 17.2%, p = 0.011).ConclusionAlteration in proximal and distal muscle activity appears to negatively affect postural control and quality of movement, which may lead to prolonged functional impairments. Hence, implementing hip and ankle muscle exercises in the rehabilitation of ankle instability might benefit these patients.

Most research on sedentary lifestyle has focused on pain and disability, while neuromuscular outcomes (postural control and strength) have received less attention. The objective of the study was to determine whether low level of physical activity is negatively associated with measures of lower body muscular strength and postural control in individuals with and without non-specific chronic low back pain (NSCLBP). Twenty-four subjects with NSCLBP (28.8 ± 5.9 years) and 24 age, gender, and body mass index matched healthy controls participated in the study. Subjects were sub-classified into 4 subgroups based on their physical activity level: Non-active NSCLBP; Active NSCLBP; Non-active healthy control; and Active healthy control. Each subgroup consisted of 12 subjects. Peak force of hip muscles strength was assessed using a handheld dynamometer. Postural control was assessed using computerized posturography and the Y Balance Test. There was no significant group by physical activity interaction for strength and static and dynamic postural control, except for static control during left single leg stance with eyes closed (P = .029). However, there was a significant difference in strength and postural control by physical activity (P < .05). Postural control and peak force of hip muscles strength were significantly associated with physical activity (r ranged from 0.50 to 0.66, P < .001 and r ranged from 0.40 to 0.59, P < .05, respectively). Postural control and hip strength were independently related to physical activity behavior. A sedentary behavior may be an important risk factor for impaired postural control and hip muscles strength, and that physical fitness is vital to neuromuscular outcomes.

Background The cross-body and the modified sleeper stretch have been used to improve posterior shoulder soft tissue flexibility and to increase glenohumeral joint internal rotation (GHJ IR) in overhead athletes. However, due to the inability to stabilize patient’s scapula and control GHJ rotation with the cross-body stretch and the potential for subacromial impingement or symptoms’ aggravation with the modified sleeper stretch, a new stretching technique (Passive Glenohumeral Internal Rotation with Clam Shell Bridging) was developed as an alternative to these commonly used stretches that may allow for greater stability of the scapula without reproducing symptoms. Thus, the current study aimed to examine and compare a novel stretching technique to the traditional modified sleeper stretch to determine the effect on glenohumeral IR range of motion (ROM) and self-reported pain in overhead athletes with glenohumeral internal rotation deficits (GIRD). Methods Forty-two overhead athletes with GIRD [mean age 25.9 ± 2.6 years, 20 males and 22 females] participated in this study. Participants were randomly assigned into either novel stretching group or modified sleeper stretching group. IR ROM was measured with a digital inclinometer before, immediately, and at week 4 post intervention, while pain was measured with Numeric Pain Rating Scale before and at week 4 post intervention. Results There was no significant group by time interaction effect for IR ROM (p = 0.27); however, there was a significant change over time (p < 0.001, η2 = 0.77). Both groups demonstrated a significant increase in IR from baseline to immediate and week 4, and from immediate to week 4 (p < 0.001). There was a significant group by time interaction for pain intensity (p < 0.001, η2 = 0.72). Results showed a significant reduction in pain intensity over time in the novel group (p = 0.001, d = 2.18), but not in the traditional group (p = 0.231, d = 0.46). Conclusion Both stretches appear to be effective at improving IR ROM in overhead athletes with GIRD. However, the novel stretching might be more effective at reducing shoulder pain and thus may be more appropriate for symptomatic patients. Trial registration Prospectively registered in February 6, 2017 under Clinical Trial Registry # NCT03044236.