Do Wall Slides do Anything?
In the wild there is a theory that exists which basically states that once a certain number of monkeys learn a behavior the whole population adopts this behavior exponentially. The hundredth monkey effect is a “supposed phenomenon in which a new behavior or idea is claimed to spread rapidly by unexplained, even supernatural, means from one group to all related groups once a critical number of members of one group exhibit the new behavior or acknowledge the new idea.” (source- wikipedia)
Genetically speaking were not so different from these monkeys, we socialize just like them, form groups just like them, eat like them and occasionally hurl feces just like them.
Well some of us anyways…
I’ve seen this hundredth monkey effect in the gym before. We see someone doing an exercise, then we see a lot of people doing an exercise and before we know it just about everyone in the gym is doing this exercise or habit. Foam rolling is a prime example, not saying there is anything wrong with that.
Today I wanted to talk about wall slides, an exercise that is touted to improve scapular kinematics as well as shoulder function.
I wanted to talk about it because I see that critical number of people doing it in the gym and I wanted to examine it before there was an eruption in the number of wall sliders.
I assume people are doing wall slides to train the muscles that are involved in scapular upward rotation. In order for a shoulder to remain healthy the shoulder blade should upwardly rotate as the arm is elevated. After the first 30 degrees of shoulder elevation the shoulder blade should begin to move. In the end the shoulder joint should move in a 2:1 ratio with the scapula, equivalent to 120 degrees and 60 degrees of motion.
People claim that forearm wall slides (facing the wall) train the serratus anterior and improve scapular upward rotation. When doing wall slides facing the wall the scapular wall slide improves activation and strength in the lower trapezius.
The muscles involved in scapular upward rotation are the serratus anterior and middle and lower traps (upper traps – about 3% contribution). So the question we need to ask is if wall slides are a valuable exercise or if there are exercises that get better muscle activation of the serratus and traps.
The research on the wall slide as a corrective exercise was a bit sparse but I did find a study that compared serratus activation between the wall slide, the plus phase of the push up plus, and scapular plane shoulder elevation.
They found that “The intensity of SA activity was not significantly different between the 3 exercises at 90 degrees of humeral elevation (P = .40). For the wall slide and scapular plane shoulder elevation exercises, SA activity increased with increasing humeral elevation angle (P = .001), with no significant differences between the 2 exercises (P = .36).” (1)
plus phase of push up plus and wall slide
The other two exercises that were tested have already proven useful in rehab and corrective settings. It seems the wall slide is no better or worse than scapular plane elevation or the push up plus.
This tells me that for a person with a healthy shoulder the wall slide and the push up plus both could be valid choices to strengthen the serratus. However, if I was dealing with a client that experienced pain overhead the push up plus might be a better suited alternative as it has the same serratus muscle activation at 90 degrees of elevation, keeping it in safer position free from impingement.
In another study on serratus anterior activation the authors concluded that, “The serratus anterior was activated maximally with exercises requiring a greater amount of upward rotation of the scapula. The exercises were shoulder abduction in the plane of the scapula above 120 degrees and a diagonal exercise with a combination of shoulder flexion, horizontal flexion, and external rotation.” (2). Shoulder abduction with elevation is essentially the wall slide with the back to the wall and flexion with external rotation mimics the wall slide while facing the wall.
To me it seems like the wall slide is a perfectly valid exercise choice if one is trying to improve scapulohumeral rhythm by improving scapular upward rotation. The wall slide may be even more applicable to overhead motions such as the overhead press when compared to exercises like the push up plus. However, the push up plus might be a better choice when dealing with a client who experiences pain in overhead activities. The ability to reach overhead is something I’ve seen people lose; wall slides can certainly help improve that pattern. So after some research I feel comfortable with the masses adopting the wall slide as a corrective exercise.
(1) A comparison of serratus anterior muscle activation during a wall slide exercise and other traditional exercises.
(2) Surface Electromyographic Analysis of Exercises for the Trapezius and Serratus Anterior Muscles
Objective: To identify high-intensity exercises that elicit the greatest level of EMG activity in the
trapezius and serratus anterior muscles