The influence of leg length discrepancy on the pelvic obliquity, scoliosis, leg strength, and leg injury in track and field athletes / 体力科学

Fifty-two trained athletes (15 short-distance runners, 20 long-distance runners, and 17 jumpers) and 5 controls were examined for leg length discrepancy, pelvic obliquity, scoliosis, leg strength discrepancy, and leg injury. Forty-seven subjects (90%) in the trained group and 4 subjects (80%) in the control group had leg length discrepancies. Differences of the femur lengths and tibia lengths, not of the joint space or soft tissue, were main factors of leg length discrepancies. There were no significant differences in leg length discrepancy and in pelvic obliquity between the trained and control groups. The trained group had twice as many leg length discrepancies and pelvic obliquities as the control group in average. A positive correlation between leg length discrepancy and pelvic obliquity was noted (p<0.001) . Among the jumpers, those who had suffered from hamstring muscle strain showed significantly more discrepancies in the right and left knee flexion strengths than the jumpers who had never experienced such muscle strain (p<0.41) . The rate of knee flexion strength against extension strength was significantly lower in the jumpers who had experienced knee joint injuries (p<0.01) .<BR>The results indicate that leg length discrepancy affects on the pelvic obliquity and scoliosis. Differences of the femur lengths and tibia lengths were main factors of length discrepancy. It is possible that an inequality of load on the right and left legs may cause leg length discrepancy.

Serum lipoprotein metabolism at rest and during sub-maximal exercise in long-distance runners / 体力科学

Five long-distance runners and five non-athletes were examined on lipoprotein metabolism at rest, during, and after pedaling exercise (60% of the maximal oxygen uptake) . At rest, the concentrations of the cholesterol (Cho.), triglyceride (TG), and phospholipid (PL) of very low density lipoprotein (VLDL) were kept at low level in the longdistance group compared with the non-athletes. The difference is significant (p<0.01) . On the other hand, the levels of the Cho, and PL of high density lipoprotein (HDL) were maintained high (p<0.05) . The concentrations of the TG of VLDL are in negative correlation with those of the Cho. (p<0.01) and PL (p<0.001) of HDL at rest. A positive correlation between Cho. and PL of HDL was also noted (p<0.001) . The TG of the VLDL decreased gradually with pedaling exercise in the long-distance group, reaching about 12 percent below the resting value just after exercise. However, no apparent change was noted in the non-athletes.<BR>The results obtained indicate that the long-distance runners, compared with nonathletes, tends to use lipids in order to produce energy for exercise. There is little possibility of transferring from the Cho. and PL of VLDL to the lipoprotein during exercise for the results of no change in concentrations of the Cho. and PL of low density lipoprotein (LDL) and HDL. We concluded that the Cho, and PL of VLDL could gradually transfer to HDL by a heap of the endurance exercise for long period.