Before any "real" training begins - muscle building hypertrophy resistance exercise, fat-burning metabolic conditioners (met-cons), heart-building steady-state cardio sessions (for those that need it) or yoga based compensations, cool downs and stretching – an assessment should be done by a qualified trainer who has the background and experience to be thorough.
If there are physical issues the trainer will see them and then craft a practice to address those concerns. If for example the trainer notices that his client has some significant shoulder rounding, or hunching, due to poor ergonomics at the client’s place of employment, and physical therapy is either not called for, or the client is post rehab, the trainer might start with some simple movements drawn from yoga or the field of Somatics to begin to realign the postural muscular systems.
The two main problems with shoulder rounding, or hunching, are usually due to an improper muscular balance between the pectoral muscles, sternocleidomastoids, scalenus anterior, scalenus medial, anterior deltoid and the posterior muscles such as the trapezious, posterior deltoid, spinal erectors, several posterior neck muscles, et cetera, and also to Sensory Motor Amnesia (SMA).
The trainer will use specific movements and isometric holds to foster a sense of how the client should hold himself, if his posture were correct – retraining the neurological system into “remembering” how it is supposed to fire signals to the musculature to hold the correct posture. This would then be reinforced through other exercises – both to bring the clients muscular balance back into check, as well as continuing to build the neurological connections (as well as the mind-body connection, as you will have to be mindful of what’s going on to make the changes as permanent as possible).
If corrective exercise isn’t done and the client starts training for some functional, attribute, or physique based goal, there is a very good chance their issues will directly lead to poor performance, injury and trauma.