Joint impingement syndrome: clinical features

Joint impingement is a painful syndrome caused by the friction of joint tissues, which is both the cause and the effect of altered joint biomechanics. From the anatomical and clinical viewpoints, these syndromes are classified as bone impingement, soft tissue impingement and entrapment neuropathy, depending on what joint portion impinges on the others. We considered the most important impingement syndromes of the upper and the lower limbs from the clinical viewpoint. As for the upper limb, supraspinatus impingement is a frequent cause of shoulder pain in both athletes and the normal population; the painful subacromial arch is a typical sign of the rotator cuff impingement syndrome and of outlet and non-outlet impingement as well. As for the elbow, we considered both medial and lateral impingement. The carpal tunnel syndrome is the most common peripheral entrapment neuropathy of the upper limb; it is caused by compression of the median nerve at the wrist. We considered the main causes of carpal tunnel narrowing and the relative clinical findings. As for the lower limb, we considered the iliotibial band friction syndrome, which is the most common overuse syndrome of the knee and the ankle impingement syndrome. The latter includes anterolateral impingement (with chronic anterolateral and lateral pain and ankle instability), sinus tarsi impingement, anterior impingement (with pain during foot dorsiflection and posterior impingement. The tarsal tunnel syndrome is the most important ankle entrapment neuropathy causing burn pain and paresthesias in the toes and sole of the foot.