“…ECS is one of many causes of extremity pain with activity. Others include medial tibial stress syndrome (16,17), stress fracture, popliteal artery entrapment syndrome, post-traumatic joint contractures/bone malalignment, lower limb length discrepancies, peripheral artery disease, inappropriate footwear, congenital foot disorders such as cavus feet or pes planus, venous stasis/lymphedema disease, and nerve entrapment (18). Etiologies may overlap such as anomalies as in our case (i.e., increased femoral anteversion, increased external tibial torsion, and hypertrophied muscle from exercise).…”