Muscular Imbalance of the ShoulderIn case of a muscular imbalance of the shoulder the strong muscles on top of the shoulder (deltoid muscle) and at the shoulder front side (pectoral muscles) severely counteract the significantly weaker muscles at the shoulder backside (the so-called external rotators). Similar to the tug of war, the stronger party will win.
In detail: The deltoid muscle is active almost throughout the day, for example: each time the arms are lifted or reached out in some way. Consequently this muscle will always remain quite strong. In opposite direction towards the bottom there are only the muscles "Infraspinatus" and "Teres Minor" which belong to the rotator cuff These two muscles should theoretically act on the humerus with so much tension that the humerus is stabilised in its capsule without being pulled upwards – against the acromion – by the strong deltoid muscle. In the course of life these two muscles, however, usually become far too weak so that they will often be no longer able to fulfil their task.
Why? Due to the anatomy of the human being the arms can mainly only be moved laterally, forward or upward. As a consequence only the muscles in the respective parts of the body – principally the deltoid muscle and the pectoral muscles - are frequently activated and thus remain strong.
The two muscles Infraspinatus and Teres Minor, however, are located in the back of our shoulder where no considerable activities take place for which both muscles would have to be activated.
And as if it would not be bad enough that these two neglected muscles are hardly strengthened, they additionally weaken. Every time we actively move our arms laterally, forward or upward, also the muscles Infraspinatus and Teres Minor are automatically pulled and stretched, which will even worsen the dilemma of "muscular imbalance". It is therefore inevitable that the rotator cuff will sooner or later will no longer be able to hold the head of the humerus in the middle of the capsule.
By the way, this also explains the fact that particularly sportsmen such as swimmers, handball-, volleyball- and tennis players as well as all further sportsmen with overhead activities already start suffering from muscular imbalances and the impingement syndrome at young age. All these sportsmen focus on activities in which the arms are moved up- and forward. Consequently they have stronger deltoid and pectoral muscles than a “usual” human being, but their muscles of rotator cuff are more stretched and weaker than normally.
The AktiFlex® ShoulderTrainer should be part of each sportsman’s standard equipment. This would help to prevent shoulder problems at an early age as well as numerous injuries and breakdowns.
Further interesting pages: Impingement | Bursitis | Calcific tenditis of the shoulder | Night pain | AktiFlex® ShoulderTrainer