With any injury, there is associated compensation. The body is very good at adapting. What this means is that the body will 'find a solution' if it cannot perform a movement utilising the known or 'normal' means of activation/contraction. (biomechanics) If a hamstring is not firing properly or is compromised, the body will utilise the power of adductors to complete a movement. If a shoulder stabiliser goes 'down', the body will recruit from another muscle in the chain to stabilise the shoulder for movement.