Clinical meaning
Musculoskeletal special tests are provocative clinical maneuvers designed to stress specific anatomical structures (ligaments, menisci, tendons, nerves) and reproduce symptoms, providing diagnostic information that guides further evaluation and management. The Lachman test evaluates anterior cruciate ligament (ACL) integrity by assessing anterior tibial translation on the femur: with the knee flexed 20-30 degrees (relaxing the hamstrings), the examiner stabilizes the distal femur with one hand and applies anterior force to the proximal tibia with the other. ACL disruption produces excessive anterior translation (greater than 5 mm compared to the contralateral knee) with a soft or absent endpoint, as the ACL normally serves as the primary restraint to anterior tibial translation. The Lachman test has the highest sensitivity (85-95%) of all ACL physical examination maneuvers. The McMurray test evaluates meniscal tears: with the patient supine and knee maximally flexed, the examiner applies valgus stress with external tibial rotation (medial meniscus) or varus stress with internal rotation (lateral meniscus) while slowly extending the knee. A palpable or audible click with pain along the joint line suggests meniscal tear, as the trapped torn meniscal...