The most common exercise I see at the ballpark these days is one which players refer to as their “tubing exercise”. It’s great to see maintenance and “prehab” exercises being involved in a player’s daily routine but there are still some problems associated with it. Not many players (or coaches for that matter) know what muscle group is being trained, why we perform the exercise or how to complete it properly. Throughout my involvement of playing, coaching and running on-field sessions I have seen this exercise done in an astounding number of ways. Figure 1 shows you the general setup so let’s break it down…
This exercise is intended to directly activate the rotator cuff (RC) muscle group or portions of it depending on the direction of pull (see previous article for rotator cuff anatomy). This muscle group can produce internal or external rotation of the humerus (upper arm bone). The naming of the movements is a product of the direction in relation to the midline of the body. Sometimes it’s difficult to visualize the rotational movement produced but simply put the humerus rotates as if it were a rotisserie spit. On average there are 70 degrees of internal rotation and 90 degrees of external rotation available at the shoulder joint (Glenohumeral Joint).
Figure 2: The humerus rotates in the shoulder joint
both internally and externally. (a) External rotation
moves the forearm through the windup phase and
internal rotation completes the throw during the
acceleration phase. The (b) nature of rotation is
determined in relation to movement direction with
respect to the midline (internal = towards midline,
external = away from midline).
High resistance/weight is certainly not the intention of the exercise, so more is not better in this case. Using the band provides low to moderate resistance for both the internal and external rotators to work against. The RC stabilizes the shoulder for every throw made so for that reason it is of the utmost importance that we train these muscles for endurance and not strength or power. The RC must be at peak function throughout an entire game or practice. That being said it is prone to fatigue and consequently loss of shoulder stability and throwing efficiency can occur. Less efficient throwing mechanics can lead to injury and/or a decrease in performance.
Many players currently perform this exercise either too fast and/or with too many moving parts. When the rest of the body is moving the exercise is no longer exclusively targeting the muscles it is intending to. Since this exercise is training a muscle group for endurance we usually stress three sets of 12-15 repetitions on a daily basis in a slow and controlled fashion of movement.
Keep in mind that this is not the only way to train your RC but for the purposes of this post we will discuss the position above as it is the most functional and applicable to baseball. The above version of the exercise is focusing on the internal rotation component of the RC. The external rotation bias is identical except the player will face the screen and the start/end positions are reversed. From the front we are focusing on a 90/90 position. This means that there is a 90 degree angle made by the torso/upper arm as well as by the upper arm/forearm. When we look from the side the only important cue is focus on being able to draw a straight line between elbow, same side shoulder, and opposite side shoulder. This alignment is key to isolate the correct muscle groups and avoid undue strain on other tissues. The movement is performed in a slow and controlled manner in both directions, controlling the movement is paramount. There should be tension throughout the entire range of motion.
Alignment – (1) 90/90, (2) straight line between elbow/shoulder/opposite shoulder
Motion – (1) slow and controlled in both directions, (2) tension in tubing throughout range of motion
Take the active approach to include preventative exercises in your routine. If you are experiencing undue arm soreness or just want to get ahead of the game all you need to do is consult your local physiotherapist for a comprehensive exercise program. Just use the “find a physio” function at BC Physio if you want to consult a physiotherapist in your area. If you have any questions or comments please feel free to include them in the comments section.