Search Results

The aim of this study was to evaluate the acute effect of the use of stable and unstable surfaces on electromyography (EMG) activity and coactivation of the scapular and upper-limb muscles during the push-up plus (with full protraction of the scapula). Muscle activation of anterior deltoid (AD), posterior deltoid (PD), pectoralis major, biceps brachii (BB), triceps brachii (TB), upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) levels and coactivation index were determined by surface EMG in 20 young men during push-up plus performed on a stable and unstable condition (2 unstable devices applied to hands and feet). The paired t test and Cohen d were used for statistical analysis. The results showed that during the execution of the push-up plus on the unstable surface an increased EMG activity of the scapular stabilizing muscles (SA, MT, and LT) was observed, while AD and PD muscles showed a decrease. During exercise execution on the unstable surface there was a higher index of coactivation of the scapular muscles (SA–MT and UT–LT pairs). No significant differences were observed in TB–BB and AD–PD pairs. These results suggest that the push-up-plus exercise associated with unstable surfaces produced greater EMG activity levels and coactivation index of the scapular stabilizing muscle. On the other hand, the use of an unstable surface does not promote the same effect for the shoulder muscles.

The purpose of this study was to determine the proprioceptive effects of ankle bracing and taping. Proprioception was assessed in 26 subjects by evaluating ankle joint position sense, which was determined by the subjects' ability to actively reproduce a passively positioned joint angle. Testing was performed at positions of 30° of plantar flexion and 15° of inversion. Each subject underwent four trials at each test angle under three conditions: braced, taped, and control. For the plantar flexion test, both the braced condition and the taped condition significantly enhanced joint position sense when compared to the control condition. There was no significant difference between the braced and taped conditions. For the inversion test, the taped condition significantly enhanced joint position sense compared to the control condition. There was no significant difference between the braced and the control conditions or between the braced and the taped conditions. This study demonstrates that ankle bracing and taping improve joint position sense in the stable ankle.

Context: Single leg balance testing is a commonly used tool in sports medicine; however, there has been no consensus on trial duration needed to obtain reliable measures. Objective: This investigation sought to determine the minimum trial duration required to obtain the highest intrasession single and average trial reliability for single leg balance testing on stable and unstable surfaces using dominant and nondominant limbs. Design: Intrasession reliability. Setting: Biomechanics laboratory. Participants: 70 healthy (35 men, 35 women), physically active young adults aged 22.8 ± 2.8 y divided into 3 subgroups (n = 10, 30, 30) across a 3-phase study. Methods: 3 phases of single leg balance testing were performed. For phase 1, the duration of time each participant could maintain posture on each limb/surface were computed. Phase 2 considered performance for 6 cumulative time intervals (5s, 10s, 15s, 20s, 25s, 30s). Phase 3 served to solidify results of phase 2 by computing reliability of 15s trials. Main outcome measures: Overall stability index of the center of pressure and platform tilt. Results: Intraclass correlation coefficients for phase 2 ranged from .74 (5s interval for nondominant limb on unstable surface) to .94 (20s interval for nondominant limb on stable surface). Phase 3 intraclass correlation coefficients ranged from .66 to .78 for single trial and .85 to .92 for 3 trial average with coefficients of variation ranging from 23.9% to 40.4% for single trial and 13.8% to 23.0% for 3 trial average. Conclusions: These results ultimately suggest 15s as the optimal trial duration to provide reliable measures while reducing compensatory event occurrence.

The purpose of this study was to investigate the effects of induced anesthesia of the lateral ankle joint on proprioception as assessed in weight-bearing and non-weight-bearing conditions. Sixteen subjects were assessed under normal conditions and following an 8-cc injection of lidocaine into the anterior talofibular ligament of the ankle being tested. Center of balance and postural sway measurements were analyzed, revealing a significant lateral adjustment of center of balance during the stable tests compared to a medial adjustment during the dynamic tests under the anesthetized condition. ANOVA of postural sway scores revealed no main effect for condition (anesthesia vs. no anesthesia), but sway scores were higher during the two dynamic conditions as compared to the stable condition. ANOVA of joint position error scores revealed no main effect for condition. Findings suggest that inhibition of the joint receptor afferent fibers adversely affected joint proprioception as assessed while subjects were weight bearing but not while they were non-weight bearing.

A 57-year-old patient who was on Coumadin was placed on a very vigorous sports medicine rehabilitation program for a left hemiparesis. His prothrombin was stable at 16 seconds with a control of 12.4 seconds. After doing knee flexion and extension exercises on an isokinetic machine, he developed an extensive posterior thigh ecchymosis. Rehabilitation clinicians need to be aware of the possibility of such a complication in an anticoagulated patient.