The effects of ankle braces and taping on lower extremity running kinematics and energy expenditure in healthy, non-injured adults.

Ankle braces and taping are commonly used to prevent ankle sprains and allow return to play following injury, however, it is unclear how passive restriction of joint motion may effect running gait kinematics and energy expenditure during exercise. The purpose of this study was to determine the effect of different types of ankle supports on lower extremity kinematics and energy expenditure during continuous running. Thirteen healthy physically active adults ran at self-selected speed on the treadmill for 30min in four different ankle support conditions: semi-rigid hinged brace, lace-up brace, tape and control. Three-dimensional lower extremity kinematics and energy expenditure were recorded every five minutes. The semi-rigid hinged brace was most effective in restricting frontal plane ankle motion. The lace-up brace and tape restricted sagittal plane ankle motion, while semi-rigid hinged bracing allowed for normal sagittal plane ankle kinematics. Kinematic changes from all three ankle supports were generally persistent through 25-30min of exercise. Only tape influenced knee kinematics, limiting flexion velocity and flexion-extension excursion. Small but significant increased in energy expenditure was found in tape and semi-rigid hinged brace conditions; however, the increases were not to any practically significant level (<0.5kcal/min).

Development of a modified Margaria-Kalamen anaerobic power test for American football athletes.

This study examined a modification of the Margaria-Kalamen test for football players. The football stair climb test (FST) protocol used in this study increased the vertical displacement (20 steps, 3.12 m) so that the mean best time for the test was 2.048 +/- 0.267 seconds. Fifty-eight Division I-A football players volunteered to participate (mean +/- SD age = 20.2 +/- 1.8 yr, height = 184.1 +/- 7.7 cm, weight = 102.5 +/- 19.4 kg). Subjects performed 25 trials with 30 to 40 seconds of rest between trials. Test-retest reliability was determined using 34 subjects by way of intraclass correlation coefficients with a value of 0.73 for peak power and SEM of 105.4 W, indicating an acceptable level of reliability. Subjects were divided into 3 groups by position: linemen (Line), skill, and linebackers (LB). Alpha level was p < 0.05. Peak power was 1674.5 +/- 300.8, 1712.6 +/- 251.5, and 1388.6 +/- 210.4 W for the LB, Line, and Skill groups, respectively. Groups were significantly different (p < 0.0001), with the LB and Line found to be more powerful than the Skill group. Peak power continued to increase throughout the 25 trials in the Skill and LB group but plateaued after approximately 17 trials in the Line group. It was concluded that the FST was a reliable test for measuring peak anaerobic power in collegiate football players, which, theoretically, should provide more accurate measures of peak power caused by increased vertical displacement and longer duration, resulting in a decreased influence of cheating strategies during test administration. To achieve maximal power in stair climbing tasks, coaches may need to incorporate a greater number of trials or a more intense warm-up than has been previously reported.