The claim that heavy weight training can damage the growth plates of prepubescent youngsters has been around for many years, but no clinical studies have yet corroborated that assertion. In fact, bone density scans have shown exactly the opposite, namely that youngsters who do weightlifting have a higher bone density than children who do not use weights. Clinical records have not shown any correlation between heavy weight training and epiphysial damage or any of those other problems that you have mentioned.
As a matter of fact, RHABDOMYOLYSIS in the healthy person is far more commonly associated with excessive amounts of strenuous muscle endurance exercise such as marathon running.
Where does that information on 'permanent adhesions' on the musculotendinous junction come from? This junction is not really a clearly defined junction, anyway. The muscle gradually becomes more and more collagenous towards its ends and in the tendon it becomes almost entirely collagenous, then as the tendon approaches the bone to which it attaches, it becomes progressively more 'bony', until it fuses into the periosteum at its bony insertion. This is a very intelligent design because a sharply defined musculotendinous junction would be more susceptible to damage than a continuum of tissue structure extending from one bony attachment to another.
It would be difficult to imagine how permanent adhesions could take place 'on' this region because of the powerful movement of the tendon during forceful movement that would tend to minimise any chance of such adhesions forming.
A close colleague of mine who is a well known orthopaedic surgeon and sports medical specialist and who has treated, operated upon or studied the joints of tens of thousands of patients of all ages over a career spanning more than 35 years reported at a sports medicine seminar that he had never been able to categorically show that any given weight training regime or vigorous sporting regime produced premature closure of the epiphyses in healthy, well nourished individuals.
A major confounding factor is that most children run, jump and carry out other very impulsive activities which impose far greater forces on the joints than squatting or deadlifting even 3 times bodymass. Many of us who have carried out research in biomechanics have shown that the forces experienced by the body during running, jumping, hitting and landing often exceed 4 times bodyweight.
While squatting or deadlifting a load of 275lbs may seem to impose huge loads on the joints of a youngster that figure can easily be doubled during running and jumping. In other words, if we are to base our judgment on the basis of magnitude of force imposed on the body, then we ought to ban all running and jumping from schools.
It is not weight training or indeed any sport per se which causes injury, but the manner in which it is performed. A technically well executed lifting exercise is perfectly safe. A poorly executed squat is just as dangerous as poor running or jumping style. Excessive intensities and volumes of weight training, running, cycling and indeed any other physical activity can produce injury.
The important point to make here is that the motor skills of all sports and physical training should be rigorously taught to children and coaches to minimise the risk of injury. That, of course, includes creating a deep awareness of the phenomenon of overtraining. It is unnecessarily alarming to single out weight training as a proven cause of epiphysial damage and retarded growth. That simply is not scientifically correct
