Grip Strength: Why It Matters For Your Shoulder

Grip Strength: Why It Matters For Your Shoulder The shoulder is a complex joint that involves many different structures and motions. It is the connection between the upper limb and torso and is highly involved in many sports/activities. This also means that it is an area that is often injured within athletic populations, including those participating in regular resistance training. It has been estimated that up to 36% of resistance training related injuries involve the shoulder complex (1). These injuries have a broad range with regards to the specific structures being affected, the type of injury, and the specific mechanisms causing the injury. These cannot only impact your performance in activities/gym, but also in your daily life.   So why does grip strength matter?  Grip strength has been shown to correlate with overall function of the shoulder. A study by Antony et al found an increase in shoulder muscle activity (increased shoulder stabilizer activation, decreased activation of compensatory muscles – anterior/middle deltoid) occurred when the amount of force used to grip increased (2). This basically means that if you squeeze your hand harder, there will be increased muscle activity in muscles that help stabilize the shoulder. Another study by Horsley et al, looked at the connection between grip strength and rotator cuff strength in healthy individuals. They found there was increased strength the rotator cuff in individuals that had higher grip strength (3). Try this!   Place your right arm at your side and your left hand on your right shoulder. You can hold onto an object, or just make a fist with your right hand.  Start to squeeze the right hand, slowly ramping up the strength till a max contraction.  You will notice that as you start to increase the strength of the contraction, the muscle activation starts to increase in the shoulder (you should feel the muscles in the arm/shoulder fire).  There have been several proposed reasons for this relationship. One involves the concept of irradiation, which entails the transmission of neural impulses from a contracting muscle to the surrounding muscles. This will not only increase the activation of the surrounding muscles, but also increase their strength output (if they are involved in the action). Another theory is that the tension/forces are transmitted via myofascial/myotendinous expansions running up the arm, providing a network for this transmission (4).   What makes up grip strength?  Most people believe that overall grip strength is purely produced by the flexors of the forearm (muscles responsible for closing the hand). But it is actually also involves the extensors of the wrist/hand (muscles that open the hand). These will act as an opposing force to the flexors to help create functional stability of the joint (4). How can this help me? Try incorporating exercises that involve the use of grip strength (carry variations, Kettle Bell “bottoms-up” presses, 1-arm hangs, etc.) into your routine. It can be beneficial to not only build muscle, but also increase grip strength.   Suitcase Carry Kettle Bell "Bottoms Up" Press Grip strength alone is not the cure for all shoulder injuries! There are many different factors to consider for each individual case and injury; this is just a small piece of a much bigger puzzle. This post is meant to shed light on an often overlooked area when it comes to shoulder health and function. If you are experiencing any shoulder pain or would like to work on preventing future shoulder issues, feel free to contact me and we can go over some options for you.    Written by Dr. Jon Perry Chiropractor 1. Kolber, M. J., Beekhuizen, K. S., Cheng, M. S. S., & Hellman, M. A. (2010). Shoulder injuries attributed to resistance training: a brief review. The Journal of Strength & Conditioning Research, 24(6), 1696-1704. 2. Antony, N. T., & Keir, P. J. (2010). Effects of posture, movement and hand load on shoulder muscle activity. Journal of Electromyography and Kinesiology, 20(2), 191-198. 3. Horsley, I., Herrington, L., Hoyle, R., Prescott, E., & Bellamy, N. (2016). Do changes in hand grip strength correlate with shoulder rotator cuff function?. Shoulder & elbow, 8(2), 124-129. 4. Robb, A., Weinberg, B. Athletic Movement Assessment Manual (Taken June 24-25, 2017).