Fundamental to the function of the human skeleton on a bicycle is the position that you adopt in your set up. When Tobina Wilson from ‘Six Physio’ set me up on my Roubaix Compact, I found that a lot of the pains that I had been experiencing early in my ride career disappeared. Simple advice about thoracic posture, and elbow position made longer rides more comfortable.
The major muscles to help with the powerful stroke on the pedals aside from the quadriceps are the gluteal muscles – the butt. However if you flex the pelvis, you incapacitate these muscles, and it is therefore of paramount importance that you flex from the hip and not from the back. This latter action will cause you intense low back pain after a while as well.
Thus the correct set up and the correct ride position are critical for power production and also for comfort.
Your ‘expert’ should help you adopt the correct saddle height. This is partly about the reach to the ground, but also about the reach to the pedal, giving you a knee position of 150-160 degrees in full down travel.
Your saddle must be comfortable and support the width of you ‘sit-bones’ (Ischial tuberosity). This is important in making you stable.
You need flexibility in your gluteal muscles, in your Iliotibial band (ITB) and minimize the side to side forces of your knee joint.
Rotational torsion of the knee is reduced if there is some rotational movement in your cleat shoe set up. Ideally a laxity or ‘float’ of about 5 degrees would be enough It must not be too rigid, as this will confer forces up your leg that will eventually lead to pain.
I would recommend Tobina and those experts like her as it is important to combine both the set up of the bike, and the exercises and stretches to ensure that your musculoskeletal system is able to cope with the rigours of a long ride.