Scapular kinematics during shoulder elevation performed with and without elastic resistance in men without shoulder pathologies.

STUDY DESIGN: Controlled laboratory study using within-group comparisons. Objectives To compare scapular kinematics between active and resisted shoulder elevation performed in the sagittal (flexion), frontal (abduction), and scapular (scapular abduction) planes. BACKGROUND: Several studies have documented scapular kinematics during arm elevation against an external load; however, there is little information on how scapular kinematics change with loading provided by elastic bands, an exercise approach often used in the clinic. METHODS: Thirty-two men without shoulder pathology participated in the study. The level of resistance to be used for each individual was determined prior to data collection and standardized by perceived effort on a Borg scale. Three-dimensional scapular kinematics were recorded with an electromagnetic tracking device in all 3 planes of shoulder elevation for both the unloaded (active) and loaded (resisted) conditions. Data for scapular kinematics were analyzed at 30°, 60°, 90°, and 120° of humerothoracic elevation and lowering. Comparisons between loading conditions were made using analysis-of-variance models. RESULTS: In general, for all 3 planes of movement, the scapula was more downwardly rotated and anteriorly tilted during the elevation phase and more so during the lowering phase of shoulder elevation when performed against elastic resistance. While some of the statistically significant differences might not have been large enough to be considered clinically meaningful, some values were of a magnitude similar to previously reported differences between healthy and symptomatic individuals. CONCLUSIONS: The changes in scapular motion during the loaded condition were relatively small in this population with normal scapular motion, but they were in a direction that would be considered to have potential to lead to injuries, suggesting caution when using these exercises in individuals with poor scapular control.

The effect of prophylactic knee bracing on performance: balance, proprioception, coordination, and muscular power.

PURPOSE: Prophylactic knee braces are largely used in the prevention of ligament injuries, but their effectiveness on performance are still controversial. The aim of this study was to determine which brace was the most effective on functional performance. METHOD: Twenty-four healthy subjects (14 men and 10 women), between the age of 18 and 22 with no prior history of lower limb injury and brace use, voluntarily participated in this study. Five different prophylactic knee braces were used. The test protocol consisted of dynamic balance, jumping performance, proprioception, coordination, and maximal force. Balance was assessed by the Y balance test; jumping performance was assessed by vertical jump and one-leg hop tests; maximal force, proprioception, and coordination were assessed by using functional squat testing. Proprioceptive test was performed by using the functional squat system machine that the participants were instructed to keep the crosshair on the line, even after the visual aid had disappeared. The subjects without a brace and with the brace by using 5 different braces (DonJoy-USA) were evaluated by five different therapists. RESULTS: Hinged "H" buttress for the support of the knee brace was found to be more effective than the others in terms of balance. Drytex economy hinged knee brace had the best result in terms of proprioception and maximal force. There were no significant differences in vertical jump and one-leg hop tests (n.s.). CONCLUSION: In conclusion, the hinged "H" buttress for support of the knee brace and Drytex economy hinged knee brace produced the best results on the performance parameters. The other three braces demonstrated more variable and less optimal results. Prophylactic knee braces can be used for both healthy subjects and athletes to enhance proprioception, coordination, maximal force, and balance, but it is important to choose the best proper brace to the individuals according to their fitness level. LEVEL OF EVIDENCE: (Economic and decision analysis-developing an economic or decision model), Level II.