Objective: The purpose of this study was to examine the strength of the knee and pulmonary function comparing collegians and hockey players in college.

Method: KINㆍCOM isokinetic dynamometer and medigraph were used to evaluate strength of the right lower extremity and pulmonary function to 30 male students comprising 15 hockey players and 15 collegians with no significant difference in age, weight, and height between the two groups. All subjects used their right lower limb as dominant limb.

Results: 1) The significant differences between collegians and hockey players were found in the peak torque at 60^o/sec,

180^o/sec. 2) The siginficant differences between collegians and hockey players were found in forced vital capacity, forced expiratory volume in one second and expiratory reserve volume on the pulmonary function. 3) The significant correlation between isokinetic strength and pulmonary function were found in peak torque.

Conclusion: It is turned out that hockey players in college have much better isokinetic strength and pulmonary function than collegians, so it is suggested this result have to be considered in selecting hockey players and exercise prescription. (J Korean Acad Rehab Med 2002; 26: 228-232)

Objective: This study was designed to evaluate the relation of leg length discrepancy on ankle muscle strength.

Method: Twenty four adult women were tested (12 leg length equality and 12 leg length discrepancy). Leg length was measured by tape ruler from anterior superior iliac spine to medial malleolus, three times by three different trained examiners. The muscle strength (bilateral ankle dorsiflexors and plantarflexors) was measured by using Cybex 340 dynamometer at 30 degree/sec and 120 degree/sec.

Results: The mean value of leg length discrepancy was 0.89⁑0.24 cm. In leg length discrepancy group, the peak torque of ankle plantarflexor were 44.50⁑20.94 Nm in long leg and 51.83⁑12.75 Nm in short leg at 30 degree/sec angular velocity (p＜0.05).

Conclusion: We concluded that there were significant increase in plantar flexor peak torques of short leg than those of long legs at 30 degree/sec (P＜0.05). Perhaps the difference of the muscle strength might be due to compensatory mechanism of short leg in propulsion during gait.

Objective: The purpose of this investigation was to document the isokinetic performance deficiencies of the invertor and evertor muscles of chronically sprained ankles.

Method: Eversion/Inversion testing was performed by a Cybex 6000 isokinetic dynamometer at the speeds of 60^o/sec and 120^o/sec on 17 subjects who had unilateral chronic ankle sprain. Values were compared between the involved and uninvolved sides.

Results: The inversion peak torque deficits between the involved and uninvolved extremities were significantly greater than eversion deficits at 60^o/sec and 120^o/sec. Evertor/Invertor peak torque ratios of involved sides at 60^o/sec were significantly greater than uninvolved sides.

Conclusion: We conclude that chronic ankle sprains associate an ankle invertor weakness rather than an evertor weakness. Ankle invertor weakness might be resulted from a disuse atrophy and painful ankle inversion. Further prospective study is needed to determine the relationship between the invertor weakness and the chronic ankle sprain.

Objective: To investigate the torque curves and heart rate responses to isometric, eccentric and concentric isokinetic exercises with a maximal voluntary contraction of the right knee and elbow joints in 30 healthy men(26.6⁑2.2 years).

Method: Subjected performed the eccentric and concentric isokinetic exercises with 10 repetitions at 60^o/sec, while performing the isometric exercises at a joint angle of 60 degrees for the same period of time with Cybex 6000. Peak torque, angle of peak torque, and total work were measured and the flexor-to-extensor ratios of peak torque were calculated.

Heart rates were recorded simultaneously at rest and immediately after the exercise, and the time required to return to the resting heart rate level was also recorded for each exercise session.

Results: Peak torque and total work for the eccentric exercise were significantly higher than those for the concentric exercise(p＜0.01) of the knee and elbow joints. Eccentric peak torques for flexors and extensors of the knee joint occurred at a significantly longer muscle length than the concentric peak torques(p＜0.01).

Flexor-to-extensor ratios of a peak torque of the knee joint between the eccentric and concentric isokinetic exercises did not show a significant difference.

Torques at a joint angle of 60 degrees were highest in the eccentric isokinetic exercise, followed in the order by isometric, and then concentric isokinetic exercises of the knee joint(p＜0.01), and concentric torque at a joint angle of 60 degrees was significantly lower than those of the eccentric and isometric exercises of the elbow joint.

The increase in heart rate and the time of returning to the resting heart rate level were independent of the size of the contracting muscle mass and the types of exercise. The increment ratio for the heart rate was 70.4⁑23.6%.

Conclusion: In conclusion, the response of heart rate to the exercise is not influenced by the contracting muscle mass or the types of exercise in a short duration of maximal voluntary contraction, implying that special precautionary measures are not required for the isometric, eccentric and concentric isokinetic exercises.

The understandings of the characteristics of eccentric exercise are very important because all sports and daily activities under the gravity force should be well coupled between concentric contraction and eccentric contraction as accelerator and decelerator respectively. We tested 40 knee flexors and extensors of 20 normal young persons at different anglular velocities of 60^o/sec and 120^o/sec using Cybex 6000(A division of Lumax, New York) isokinetic dynamometer in order to know the characteristics of eccentric isokinetic contraction parameters by comparing with concentric isokinetic parameters.

Compared to the concentric isokinetic contraction, eccentric isokinetic the peak torque and average power values of knee extensor and flexor muscles showed negative values which means that eccentric contractions were coupled with concentric contractions as decelerator and energy absorptioner. The peak torque values of eccentric contraction were 38∼61%, 44∼79% higher in flexor and extensor, respectively than those of concentric contraction and not so decreased as the peak torque of concentric contraction decreased in high angular velocity. The average power values of knee flexor and extensor muscles were definitely low in eccentric contracton than those of concentric contraction but were increased simultaneously with high angular velocity contraction. Further studies about the velocity dependency, muscle soreness, methodology to measure real eccentric activities and other parameters of eccentric contraction are needed imminently.