Specific factors that influence deciding the takeoff leg during jumping movements

The definition of the dominant leg (lateral dominance) is not clear, and there has been little reporting related to lateral dominance in the legs. To uncover the practical factors influencing which leg to use as the takeoff leg in 1-legged jumping movements, this study aimed to investigate the subjective dominance side of fundamental movements and to examine the lateral dominance of motor functions between the takeoff leg and non-takeoff leg. The subjects consisted of 27 young men who exercised regularly. They had not trained particularly on unilateral jumping. Fifteen men are the athlete group (left-legged jumpers group [LG]) using a left leg and 12 men are the athlete group (right-legged jumpers group [RG]) using a right leg as determined by a preliminary survey related to takeoff leg during high jump. The fundamental motions of the subjective dominant leg were investigated and the differences between the motor functions of takeoff and lead legs, such as sole shapes, single-leg vertical jump, 20-m hopping, ladder hopping, single-leg balance, and isokinetic strength were examined. It was found that many RG subjects (83%) tended to select the right leg for hopping, and many LG subjects (87%) tended to select the left leg for 1-legged balance. It was suggested that skilled movements show right-leg dominance in both takeoff leg groups. In the LG subjects, the left leg showed a higher value than the right leg in sole shape. The RG subjects showed a higher value in the right leg than in the left leg in a single-leg vertical jump. However, marked dominance was not found in the takeoff leg. The lower limbs may not show marked lateral dominance such as in the upper limbs.