If you get a bike fit, more than likely you’ll have your hip angle assessed. The hip angle relates to the angle between your upper leg (femur) and torso – measured from your hip to your shoulder. While simplistic, this angle assesses how upright the upper body is.
The issue with the hip angle is representative of a larger issue with most all bike fits – a lack of understanding of the body in respect to how it functions as a whole and also how it interfaces with the bike.
ISSUE #1: NOTHING FUNCTIONS IN ISOLATION
Movement at a particular joint not only affects that joint but likely many other areas of the body. Therefore, when making a change to your position on the bike, your body must be addressed as a whole unit. In respect to the ‘hip joint,’ increasing/decreasing the joint angle will likely affect the tension on the hamstrings and hip flexor muscles due to the pelvis tilting. This is because the hamstrings attach to the pelvis so any forward or backward tilt of the pelvis will affect the tension of the hamstrings. This, in turn, affects your reach (arm angle) and neck/head position.
ISSUE #2: MISSING THE MAIN ISSUE
As noted above, the hip angle measurement is most commonly assessed by measuring the angle between the femur and the upper body. The upper body is assessed by making a straight line from the hip (greater trochanter) to the shoulder. So what’s the issue? The upper body aspect of the angle negates any flexion or extension of the spine. A cyclist could position their back in a flat, hyper-extended or hyper-flexed (rounded) position and not change the angle of the upper body with respect to measuring the aforementioned positions (hip/shoulder). Changes in back position (i.e., flexed/extended) are largely due to forward and backward rotation of the pelvis and greatly affect the efficiency, aerodynamics, and position sustainability of a cyclist – all very important factors.
One example of why the back position (curvature) is important is power generation. A hyper flexed back position will likely flex when a cyclist is fatigued and/or pushing hard on the pedals. Flexion of the spine absorbs energy that should be going into the pedals. This is an example of how the back position affects efficiency.
By negating the curvature of the back, you are leaving a very important factor out of the bike fit.
ISSUE #3: NOT EVERYONE IS CREATED EQUAL
Some bike fit protocols suggest a pre-determined hip angle while others suggest a range. Regardless, until a cyclist is assessed (especially their hamstring flexibility), the hip angle cannot be accurately ascertained. A lot of bike fitters and cyclists recommend having an ‘open’ hip angle – meaning, a position where the upper body isn’t too low. This is in contrast to a ‘closed’ hip angle which insinuates an upper body position that is close to horizontal.
The reality is that there is no right or wrong hip angle. Due to flexible hamstrings that allow for substantial forward pelvic tilt, some cyclists can ride with their upper body in a horizontal position with no issues. Conversely, other riders with tight hamstrings may struggle to have a 45-degree upper body angle (if measured by the traditional method).
ISSUE #4: BODY FIRST, BIKE SECOND
Due to a lack of knowledge of the body, most bike fits look to ‘fix’ biomechanical issues via modification of the bike. This is largely a Band-Aid approach. This is akin to treating the symptom and not the cause of an ailment. For example, let’s say that a cyclist has substantial forward back curvature in their low (lumbar) and mid back (thoracic) regions. A fitter notices this and in response, they move the saddle forward and raise the handlebars. Did they fix the issue from a visual standpoint, yes. However, by moving the saddle forward and the handlebars upward, the demand put on various muscles change. If the back curvature issue is due to tight hamstrings that cause the pelvis to ‘tuck under’ and this imbalance is not addressed muscularly, the issue will still be there, regardless if the back position ‘looks right.’
Therefore it is strongly advised that if you have substantial biomechanical deviations in your form and/or pedaling mechanics, or have prolonged or pain when riding, you should seek out a physical therapist (PT) that can evaluate you. While most cyclists do not seek out a PT to assist in their form, they should.
Bike fits are a great way to become more efficient, aerodynamic and comfortable while cycling. When seeking out a fitter, look for someone who has a lot of experience versus someone with the latest technological assessment gadget with limited experience.
Pre-screen them. Tell them the main reason why you are thinking of getting a bike fit to hear what their approach will be. Ask them if they have ever had others with the same issue and if you can contact them.
Ask questions. As noted above regarding the hip angle, just because an angle is being measured does not mean that it is necessarily imporant or useful. The most important thing that you can do when getting a bike fit is to be involved in the process. If a fitter cannot explain why they are assessing a particular area or making a particular adjustment, you might want to seek out another expert.
Lastly, as for the hip angle, the amount of back curvature (both flexed and extended) is a much more important metric than the conventional way of assessing the angle. If your fitter includes the hip angle in the bike fit, make sure that back flexion and extension are also taken into consideration.