Abstract
The purpose of this study was to obtain suggestions for training when aiming for a return to competition by a 400m sprinter following hamstring injury through observations of muscle strength recovery, emotional changes, and training content in a series of rehabilitation processes. Knee flexion/extension torque measurements using Cybex, subjective evaluation of pain, and range of motion tests of the hamstrings were investigated longitudinally for 72 days. The subject was able to return to competition early and updated his 400-m university best without reinjury. We were able to obtain the suggestions for training, as shown below. 1) receiving acupuncture treatment from a rest period enables early resumption of training, 2) middle power training using a bicycle ergometer is effective in improving speed endurance, 3) evaluation of knee flexion/extension muscle strength ratio and left/right difference using Cybex can be used as a guideline for return to competition, 4) psychological fear can be dispelled by participating in a competition, and 5) in order to achieve high performance without reinjury in the return competition, the 400-m sprinter should adopt a race pattern that maintains the sprinting speed in the second half of the race.
