Sunday, June 19, 2011

Spinal Posture in Cyclists

I have long wondered about the long term effects of being bent over a set of handle bars for many hours each week as per elite cyclists or triathletes, or really any person who cycles frequently. Over the last twenty odd years I have worked with many cyclists and triathletes and low back pain was not uncommon in this group and I always believed that there was a simple connection between the lumbar and thoracic posture assumed on the bike with the associated back pain or change in spinal curves. Till now I had not ever found any research based evidence to support or change my thoughts on the matter.

The paper by Muyor and colleagues (link attached) helps provide a little more detail into this aspect and if you are a strength or fitness coach working with these athletes is well worth the read. For those of you who just want the nuts and bolts of this study, I will briefly explain them.

Subjects included elite and masters cyclists and the aim of the study was to compare the spinal postures between the two cycling groups. Sagittal spinal curvatures and pelvic tilt were measured in the standing position on the floor and while sitting on a bicycle with different handlebar-hand positions using a Spinal Mouse system. The Spinal Mouse is an electronic computer-aided measuring device, which measures sagittal spinal range of motion and intersegmental angles in a non-invasive way, a so-called surface-based technique. Prior to taking measurements, the main researcher determined the spinous process of C7 (starting point) and the top of the anal crease (end point) by palpation and marked the skin surface with a pencil. The Spinal Mouse was guided along the midline of the spine (or slightly paravertebrally, particularly in thin individuals with prominent processus spinous) starting at the processus spinous of C7 and finishing at the top of the anal crease (approximately S3). For each testing position, the position of the thoracic (T1-2 to T11-12) and lumbar (T12-L1 to the sacrum) spine and the position of the sacrum and the hips (difference between the sacral angle and the vertical) were recorded. Negative values corresponded to lumbar lordosis (posterior concavity). With respect to the pelvic position, a value of 0ยบ represented the vertical position. Thus, a greater angle reflected an anterior pelvic tilt, and a lower angle (negative values) reflected a posterior pelvic tilt.


“No significant differences between elite and master cyclists were found in thoracic kyphosis and lumbar lordosis while standing on the floor. The elite cyclists showed lower thoracic kyphosis in the three handlebar positions compared to the master cyclists, but they were only significantly different in the upper handlebar-hand position (p < 0.05). The lumbar curve changed from lordosis in standing to kyphosis on the bicycle. The elite cyclists showed greater lumbar flexion than master cyclists. For all of the postures evaluated, the elite cyclists showed greater pelvic tilt than the master cyclists (p <0.05). The lumbar angle changed from lumbar lordosis in standing to lumbar kyphosis when sitting on the bicycle. The effect size was large in both groups (d = 0.99 in elite and master cyclists). A greater intervertebral flexion in the lower handlebar-hand position compared to the upper and middle handlebar-hand positions was found but a small effect size between these positions was found. The pelvic tilt was significantly more flexed when sitting on the bicycle in the lower handlebar-hand position than in the other postures, although the effect sizes were small (d between 0.1 and 0.2 in elite cyclists and 0.1 and 0.3 in master cyclists). A higher percentage of hyperkyphotic postures in standing on the floor were found in the elite cyclists. However, master cyclists had a higher frequency of lumbar hypolordosis.”

1.      Training volumes and prolonged sitting in the cycling posture may lead to changes in sagittal plane curves of the spine. There appears to be a direct relationship between training hours per year or time in years before this happens.
2.      Cyclists adopt a more thoracic curve and kyphotic lumbar when cycling and this tends to produce a more anterior tilt in cyclists when standing.
3.      Sitting on the bike with more anterior tilt or tilt of the seat may reduce low back pain in cyclists

My take on this and what it means to you as a strength or fitness coach.

We probably all understand the implications of altered posture whether it be from sitting on a bike for long hours or in a chair in front of a pc (straightening as I write) and whilst this research may not be a surprise to many of you, it really confirms this scenario. That’s the great thing about research; in fact research is often conducted to verify common held beliefs not always to find out something that’s new.

The other key aspect regards posture is the question of should we change posture because we can see it’s not normal or should only we address postural issues when loss of function or pain is present? Personally I allow for a clients current posture when developing the program plan and selecting exercises, but I also know from my own experiences that changes in posture do not always result in performance improvements.
If you are dealing with athletes who cycle as part of the training regimen, certainly consider the length of time the athlete has spent in the saddle and determine if this has started to alter the persona posture. If pain is present along with a more anterior tilt then certainly start to consider options on how you might address this issue and provide suitable stretches or exercises to assist with improving muscle function of this area. I always look for good glutes and stability of the lumbar pelvic region first and then worry about flexibility second. Proximal stability provide distal flexibility.

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