EVALUATION OF THE THIGH MUSCLES AFTER KNEE EXERCISE ON A CYBEX-II

We investigated the degree of local heat and swelling of the thigh mus cles produced by exercise. Eleven university athletes aged from 19 to 23 years old performed isokinetic exercise of the right knee on a Cybe x II. Then serial determination of thigh circumference and thigh tempe rature (up to 120 min after exercise) as well as serial magnetic reson ance (MR) imaging (up to 60 min after exercise) was per-formed on both thighs. The circumference of the right thigh peaked at 5.6 +/- 2.1 mi n after exercise and returned to normal at 38.6 +/- 9.2 min. The tempe rature of the right thigh peaked at 1 4.2 +/- 5.7 min after exercise a nd was not normalized after 120 min except in two subjects. T2-weighte d MR images showed a marked increase in the signal intensity of the ri ght knee flexor and extensor muscles. The signal intensity peaked imme diately after exercise and subsequently decreased gradually but did no t return to normal after 60 min in some muscles. Changes in the thigh circumference were closely correlated with changes in the NIR findings . The changes in the thigh muscles after knee exercise could be demons trated using MR imaging, thigh circumference, and thigh temperature da ta. These parameters may provide indicators for managing muscle fatigu e and recovery.