HOW GRIP STRENGTH IS AN INDICATOR OF LATERAL ROTATOR HEALTH?
A strong correlation between grip strength and lateral rotator strength has previously been demonstrated (Horsley, 2016)
This suggests that grip strength assessment could be used as a monitor (among other things) of rotator cuff recruitment capacity. Could we use the hand to better recruit our rotator cuff (set of key muscles in the stability and health of the shoulder)? It may well be so!
The impact of pain on grip strength
To get closer to the “clinical” side, in patients with shoulder pain related to the rotator cuff, the grip strength on the side with the painful shoulder is reduced compared to that on the healthy side (Kachanathu, 2019 ). Sporrong had already linked grip strength and rotator cuff activation in the mid-1990s (Sporrong, 1996).
Hypotheses on the link with the rotator cuff
This would be explained by the irradiation which is automatically set up in the human body when we activate a muscle of a myofascial chain strongly. Indeed, its contraction spreads to all the other muscles of the chain, prompting them to contract strongly too. We could also evoke another hypothesis: the neuro-muscular system would seek to stabilize as much as possible all the joints involved between the load (a weight or a rubber band on an external rotation movement for example, which we would squeeze very hard) and the joint that actually performs the movement (the shoulder in our example of external rotation).
Hypotheses on the link with the rotator cuff
The neuro-muscular system would therefore seek to stabilize the wrist, the elbow and the shoulder with a global muscular contraction, to best transmit the forces. All of this, however, remains only hypotheses to explain the increase in rotator cuff activity when we activate the grip very hard.
TAKEAWAY
It would therefore be relevant to ask your patients (or clients) to squeeze the load or the tool they use very hard on exercises that target their rotator cuff.
The K-Grip Dynamometer is extremely versatile and easy to use for assessing the grip strength of your patients or athletes. Why not also use it to stimulate them to properly activate their rotator cuff on movements dedicated to the shoulder?