10/23/2016
We know that full range of motion (ROM) exercises are superior for building muscle size, compared with partial ROM exercises.
And although strength gains are always joint-angle specific, we know that full ROM exercises tend to display less joint-angle strength specificity compared to partial ROM exercises. Although strength gains are joint-angle specific (to the joint angle where the peak contraction occurs), they are much more joint-angle specific after partial ROM training, than after full ROM training.
This is because the joint-angle specificity after full ROM training occurs because of regional hypertrophy (so it has a lot of carry-over to all joint angles), while the joint-angle specificity after partial ROM training occurs because of increases in joint-angle specific neural drive (which does not transfer to other joint angles).
Many sporting movements, such as vertical jumping and sprinting, require a considerable amount of lower body strength. In reality, this strength is specific to joint angles that correspond to fairly partial ROMs (because the knee is rarely bent very much during the ground contact phase of vertical jumping and sprinting). So theoretically gains in jumping and sprinting should be better after partial ROM training, compared to after full ROM training.
However, in untrained and intermediate lifters, gains in strength at any joint angle are most easily achieved by increasing muscle size. In contrast, in more well-trained athletes, gains in muscle size are harder to achieve, so there is a greater opportunity for partial ROM exercises to achieve the neural adaptations that lead to superior gains in joint-angle specific strength, and transfer better to improvements in athletic performance.
This may explain why partial squats are so effective in a group of well-trained athletes, as reported in this study.
