While no “ideal” cycling posture has been established, the position that is commonly suggested is that the lower back should be in a neutral position, that the pelvis should be positioned in an anterior tilt and that the forward flexion should be generated through hip flexion in order to flatten the kyphotic lumbar curve.
Observations of high level cyclists showed that a lower (flexed) position was achieved by flexing hips and making the pelvis more level without significantly flexing the lumbar spine and changing disc angles, even during time trial positions. (Usabiaga 1997).
Flexing at the hips appears to be key in both obtaining a low position and reducing lower back pain, as excessive sustained lumbar flexion could potentially lead to the development of lower back pain. Restriction in the range of hip flexion necessary for forward reach to the handlebars might be compensated for by the relatively less stiff back extensors creating hyper-flexion of the spine.
Although most cyclists adopt a position of lower back flexion, it has been shown that cyclists with lower back pain assume a position of greater lower back flexion on the bicycle compared to those without back pain. Increased lower back flexion is thought to impair optimal muscle activation, reducing control and stability of the spine, and place increase strain on spianl structures.
Achieving a cycling posutre with the majortiy of flexion through your hips will reduce the amount to flexion required through the lower back and reduce the changes developing lower back pain. The photo below depicts a beautiful flexed aero position with minimal spinal flexion due the ability to achieve this position through hip flexion.
Major contributors to reduced hip flexion
The hamstrings, gluts, posterior hip and lower back muscles make up what is commonly referred to as the “posterior chain.” These muscles are crucial in generating power, controlling the hip and coordinating the pedal stoke (directing power effectively to the crank) and are therefore prone to overuse and tightness.
Restriction in these muscle groups has the potential to not only reduce hip flexion but also reduce activation and ability to generate force.
Improving and maintaining adequate hip flexion can not only relieve spinal flexion but also allowing freedom of pelvic movement, ensuring that the cyclists can position their pelvis on the saddle for maximum comfort and power output.
Measuring hip flexion range of movement
You can use the following quick, easy tests to assess hip flexion range of motion
Straight leg raise. (SLR)
Lying on your back with your spine relaxed, raise your leg as far as possible flexing from your hip – ensure that your knee remains straight. You can use your hands behind your thigh to support your leg and reduce muscle activation.
Stop your leg when you feel resistance and your lower back starts to flex - you can allow a little rotation of your pelvis.
If you want a low, aero position on the bike your leg should get to around 80-90 degrees (especially for time trailing)
Lying on your back with your knee bent, move your hip to 90 degrees (thigh vertical). With your hands supporting behind your thigh (so your muscles are relaxed) straighten your knee as much as possible until resistance if felt (usually in the hamstrings) and before your spine flexes.
This test determines how much hamstring flexibility is contributing to hip flexibility. Eg. If you have a lower SLR measurement and a lower hamstring 90/90 measure, chances are that tight hamstrings are the major contributor to reduced hip flexion. However, if you have a lower SLR and a good hamstring 90/90 measurement then reduction in hip flexibility may be more from tightness in the gluts and/or spinal muscles.
Improving hip flexion range of motion
Some key techniques that I have found to be effective in maintaining and improving hip flexion in cyclists:
Avoid sitting (eg. At the office or in front of the TV) directly after cycling. This will lead to muscles cooling in a shortened position, especially the hamstrings.
This stretch was very effective for our riders when having to travel in the bus after a days cycling, placing their legs up on the seat in front of them. This stretch can be sustained for a long period of time allowing the muscles of the ‘posterior chain’ to cool down in a lengthen position
Posterior hip rotator muscles
These muscles lie behind the hip and control the hip and thigh during the pedal stroke, both in forward-backward and rotational directions. Although these muscles are primarily rotators of the hip, tightness in these muscles can contributor greatly to a reduction in hip flexion range of movement.
Effective lengthen techniques include rotation stretches (such as the one shown – pic) ensuring the hip is both flexed and rotated, and self massage using a trigger ball – (shown in pics) to release tightness and relax the muscles.
Photo Credit: Graham Watson / Cycling Australia