When a runner presents with lateral thigh pain, they are often diagnosed with ITB Syndrome. This is in no doubt a likely cause of their symptoms. Not only does the ITB assist in movement of the lower extremity, but it also serves as a shock attenuator. When running, the ground reaction forces can be as high as 7 times one’s bodyweight; with Wolff’s Law in mind, which states tissue in a person will adapt to the loads under which it is placed, it is easy to understand why the ITB can become so tough and restricted in long distance runners. ITBS is diagnosed with positive tenderness to palpation along the ITB, as well as with positive tissue length tests (Ober’s Sign).
Another common cause of lateral thigh pain in runners, which is often misdiagnosed as ITBS, is Meralgia Paresthetica. This is where the Lateral Femoral Cutaneous Nerve (LFCN) is compressed in the area around the ASIS. Symptoms are often reported as a dull ache, numbness, or parasthesias in the anterolateral thigh. Runners are often very restricted and dominant in their hip flexors, which is also a common reason for hamstring strains in runners (the hip flexor restrictions can cause reciprocal inhibition of the gluteals, leading to compensation with the hamstrings). With the restrictions in the hip flexors, and the repetitive use of the muscles, neuropraxia of the LFCN can occur. Meralgia Paresthetica can be diagnosed with symptom provocation of resisted or repetitive hip flexion. There may be correlating tightness or tenderness of the ITB, but their symptoms will be most aggravated with repetitive hip flexion and likely uninvolved with knee movement.