Coaches yell and scream at kids to achieve a proper movement in the poor, unfortunately their bodies, not their intellect or willingness prevents achievement. One problem area, especially in short axis strokes is the thoracic spine. Allan wrote thoracic spine and undulation part I and part II and he even discussed methods to improve these areas of the thoracic spine in his trouble shooting series, thoracic spine.
Hopefully, these pieces make a strong case for role of the throacic spine in swimming. A recent study looked at bilateral (both arms) shoulder flexion and the role of the thoracic spine. This study found:
"The mean±SD increase in thoracic extension with bilateral arm elevation was 12.8±7.6° and 10.5±4.4 when measured from the radiographs and photographs, respectively. There was a significant correlation between the radiographic and photographic measurements of the amount of neutral thoracic kyphosis measured in neutral posture (r=0.71, p<0.01) and for the kyphosis measured while in full bilateral arm elevation (r=0.82, p<0.001). The mean difference between the 2 measurement techniques was 2.1 degrees for kyphosis measured in neutral posture, and 0.5 degrees when measured in full bilateral arm elevation. The thoracic kyphosis angle measured in neutral posture was strongly correlated with the thoracic kyphosis angle measured in full bilateral arm elevation when measured with both radiographic (r=0.78, p=0.001) and photographic (r=0.84, =0.001) techniques.
In asymptomatic men, bilateral arm elevation is associated with movement of the thoracic spine towards extension but the amount of movement is variable among individuals (Edmondston 2012). "
Image if your swimmer is lacking approximately 10° of shoulder flexion due to a stiff thoracic spine! How are they going to reach maximally during freestyle or press their chest on fly, if their arms are stuck at 170°? Teach them these tools out of the water and give them the necessary range of motion for success, remember if a swimmer has failed to learn, you have failed to teach!
1. Edmondston SJ, Ferguson A, Ippersiel P, Ronningen L, Sodeland S, Barclay L. Clinical and Radiological Investigation of Thoracic Spine Extension Motion During Bilateral Arm Elevation. J Orthop Sports Phys Ther. 2012 Apr 20.