What is TFL pain?
Simply so, what causes TFL pain?
An intense activity like tennis can easily overwork the TFL and cause a build-up of trigger points. Additionally, prolonged sitting and sleeping with your knees up keep the muscles shortened and support the trigger point build-up. Pain from trigger points in TFL can be felt in the hip or down the leg.
Moreover, what does your TFL do?
The tensor fasciae latae works in synergy with the gluteus medius and gluteus minimus muscles to abduct and medially rotate the femur. The TFL is a hip abductor muscle. To stretch the tensor fasciae latae, the knee may be brought medially across the body (adducted).
Tensor Fascia Lata is one of those muscles that I work on with people frequently; it loves to get short and tight. When this muscle gets tight, it makes it hard for your hip to sit in a neutral or centered position in its socket; TFL can drag the ball of your hip too far forwards in the joint.