Scapula-focused exercises with or without biofeedback increase corticospinal excitability in recreational overhead athletes with shoulder impingement.

CONTEXT: Individuals with shoulder impingement syndrome (SIS) exhibit changed corticospinal excitability, scapular kinematics, and scapular muscle activation patterns. To restore the scapular kinematics and muscle activation patterns in individuals with SIS, treatment protocols usually include scapula-focused exercises, such as scapular orientation training and strength training. OBJECTIVE: To investigate whether these two types of scapular exercise can reverse the changed corticospinal excitability of recreational overhead athletes with SIS. DESIGN: Randomized Controlled Clinical Trial. SETTING: University laboratory. PATIENTS OR OTHER PARTICIPANTS: Forty-one recreational overhead athletes with SIS (n=20 in the scapular orientation group with age= 26.45±4.13 years; height= 171.85±7.88 cm; mass= 66.70±10.68 kg; n=21 in the strengthening group with age= 26.43±5.55 years; height= 171.62±5.87 cm; mass= 68.67±10.18 kg). INTERVENTIONS: Both groups performed a 30-minute training protocol consisting of three exercises to strengthen the lower trapezius and serratus anterior muscles without overactivating the upper trapezius. Participants in the scapular orientation group were instructed to consciously activate their scapular muscles with electromyographic biofeedback and cues, whereas the strengthening group did not have biofeedback or cues for scapular motion. MAIN OUTCOME MEASURES: Corticospinal excitability was assessed using transcranial magnetic stimulation. Scapular kinematics and muscle activation during arm elevation were also measured. RESULTS: After the training, both groups demonstrated a significant increase in motor evoked potentials in lower trapezius (P=0.004) and significant increases in scapular upward rotation (P=0.032), lower trapezius activation (P<0.001), and serratus anterior activation (P<0.001) during arm elevation. Moreover, the scapular orientation group showed higher lower trapezius activation levels during arm elevation following the training, compared with the strengthening group (P=0.028). CONCLUSIONS: With or without biofeedback and cues, scapula-focused exercises improved scapular control and increased corticospinal excitability. Adding biofeedback and cues for scapular control during exercise helped facilitate greater lower trapezius activation, and thus, feedback and cues are recommended during scapula-focused training.

Investigation of clinical effects of high- and low-resistance training for patients with knee osteoarthritis: a randomized controlled trial.

BACKGROUND AND PURPOSE: Muscle strength training is important for people with knee osteoarthritis (OA). High-resistance exercise has been demonstrated to be more beneficial than low-resistance exercise for young subjects. The purpose of this study was to compare the effects of high- and low-resistance strength training in elderly subjects with knee OA. SUBJECTS AND METHODS: One hundred two subjects were randomly assigned to groups that received 8 weeks of high-resistance exercise (HR group), 8 weeks of low-resistance exercise (LR group), or no exercise (control group). Pain, function, walking time, and muscle torque were examined before and after intervention. RESULTS: Significant improvement for all measures was observed in both exercise groups. There was no significant difference in any measures between HR and LR groups. However, based on effect size between exercise and control groups, the HR group improved more than the LR group. DISCUSSION AND CONCLUSION: Both high- and low-resistance strength training significantly improved clinical effects in this study. The effects of high-resistance strength training appear to be larger than those of low-resistance strength training for people with mild to moderate knee OA, although the differences between the HR and LR groups were not statistically significant.

Shoulder dysfunction assessment: self-report and impaired scapular movements.

BACKGROUND AND PURPOSE: Shoulder dysfunction is common in various patient populations. This investigation was performed to assess shoulder dysfunction with self-report and performance-based functional measures. SUBJECTS: Fifty men (25 with shoulder dysfunction and 25 without shoulder dysfunction) participated in this study. METHODS: Self-report functional disabilities were assessed with the Flexilevel Scale of Shoulder Function (FLEX-SF), and electromagnetic tracking sensors were used to monitor 3-dimensional scapular movements during 4 functional tasks. RESULTS: Relative to the control group, the group with shoulder dysfunction showed significant alterations in scapular movements (averages of 6.9 degrees less posterior tipping, 5.7 degrees less upward rotation, and 2.3 cm more elevation). Scapular kinematics correlated significantly (r) with the Self-report FLEX-SF measure during functional tasks (posterior tipping = .454 to .712, upward rotation = .296 and .317, and elevation = -.310). DISCUSSION AND CONCLUSION: Functional disabilities were identified with self-report and performance-based functional measures. The inadequate scapular posterior tipping and scapular upward rotation as well as the excessive elevation may have implications in planning intervention strategies for people with shoulder dysfunction.