This Week's Article: A Perfect Aero Position
Many triathletes experience low back tightness, occasional back discomfort, and sometimes even debilitating pain when riding in the aero position. The more "closed" the angle between the hip and the torso, the more the low back muscles are stretched, resulting in a constant tight feeling while riding. For a cyclist with poor back and hamstring flexibility, or a history of low back injury, prolonged time spent in this position can lead to severe discomfort while riding.
A forward pelvic tilt, or rotating the hips forward in the saddle, can often alleviate this problem. However, this is a function of both bike setup and proper cycling biomechanics, and most cyclists instead attempt to reduce strain on the low back by "reaching" for the handlebars with outstretched or locked out elbows. For triathletes, opening up the elbow angle in the aero position (and thus sacrificing aerodynamics) is another common sign of an attempt to reduce low back tightness.
Bike setup changes that can be made include: 1) raising the stem height to open up the torso component of the torso/low back angle; 2) increasing the seat tube angle (i.e. move from 74 to 77 degrees); or 3) shifting the seat horizontally forward. Unfortunately, Option 1 increases drag and reduces speed as the torso opens up "into the air". Option 2 will work in moderation, but as the seat tube angle becomes more extreme, potential power production, especially from the quadriceps, becomes smaller. Option 3 will also work, although it can be risky to shift weight towards the front of the bike, not only because handling becomes more difficult, but also because micromotion in the steering tube increases, which results in a speed loss to horizontal wheel movement.
An ideal solution would be to 1) increase low back and hamstring flexibility, and 2) learn to rotate the hips forward, or "push the butt back" while riding. Option 1 is a simple matter of stretching, which is why I recommend a yoga or flexibility class for triathletes with tight backs. Option 2 is a matter of practice. Simply focus on slight hyperextension in the low back, which is best achieved by "opening" the rib cage, or pushing the ribs slightly forward, while pushing the butt back. This opens the hip/torso angle and reduces low back stress, but takes quite a bit of focus to teach your body to ride in this position. You may also find that when you rotate your hips forward, especially if you are a male, that more of the pelvic area contacts the fairly uncomfortable nose of the saddle. Tilting the saddle slightly downward can help alleviate this problem.
Once you've adopted the hips forward position, you will find that drag is reduced, speed is increased, the lungs are opened, and low back tightness is decreased. You're another step closer to a perfect aero position.
Until next time, train smart,
Ben Greenfield