Take a look around next time you're at the gym and observe the various ways people perform pull-ups. Odds are you'll see several different methods (some with good form, some with poor form). Do you know why people choose the method they do? We thought we'd look at some of the differences between wide-grip and close-grip pull-ups with Jim. As we've discussed before, Jim does have a history of some shoulder issues on his right side, which may be the cause of some differences in neuromuscular control on the right side compared to the left.
One of the things that stood out to us from the posterior view was the decrease in smoothness of scapulohumeral rhythm on the right side compared to the left. You can almost see the scapula "jump" at a couple different points where muscles are not being appropriately activated. Another interesting observation was the difference in trapezius activation during the close grip vs. wide grip pull-up. During wide grip, you can see much more trapezius activation along the vertebral column. Because wide grip is a more difficult motion, the latissimus dorsi is being forced to work harder and the trapezius is attempting to stabilize. Because of a history of pathology to the right shoulder, it was evident that he was incorporating his upper trapezius significantly more at the end-range of wide grip pull-ups, especially on the right side (this may be due to weakness of the latissimus dorsi). This can be observed by viewing slight scapular elevation on the right and noticing a decrease angle between his head and shoulder at end-range.
As you can see, Jim had become fatigued after doing 12 pull-ups. What's interesting is that you can see towards the end here, his lower body starts to shift forward with hip flexion, allowing his pecs and biceps to have a larger impact on the exercise (not to mention the fact that his chin is no longer making it to the top of the bar!). It's at this point that we would have our patients either take a break or move to another exercise as he is unable to maintain the proper form. The exercise is no longer achieving the desired purpose. Additionally, as mentioned above on the posterior view as, from the lateral view one can really see how much more latissimus dorsi activation is required with wide-grip. Jim was able to perform close-grip much more easily because he could use his arm musculature to assist with the last 30 degrees of motion. The arm muscles are put at a relative mechanical disadvantage in wide-grip. Combine that with fatigue and it is evident why he struggled with the last 2 wide grip pull-ups. What are your thoughts?