Musculoskeletal Physical Examination Basics

Mastering the musculoskeletal physical exam is a cornerstone of clinical medicine. Whether you’re evaluating a sprained ankle or investigating chronic back pain, a systematic approach allows you to efficiently localize the problem, formulate a differential diagnosis, and determine the need for further imaging or referral. This fundamental skill transforms a list of patient symptoms into actionable clinical findings.

Inspection: The Visual Foundation

The examination begins the moment the patient enters the room. Inspection is a deliberate, structured observation for asymmetry, deformity, swelling, discoloration, and muscle wasting. You should compare the symptomatic side to the contralateral, unaffected side. Look for postural abnormalities, such as kyphosis or scoliosis in the spine, or carrying-angle deformities at the elbow. Observe for effusions—swelling within a joint—which may present as loss of normal contours, like the hollows around the patella (knee) becoming full. Also note skin changes, scars, or erythema. A patient with a rotator cuff tear, for instance, may exhibit atrophy of the supraspinatus or infraspinatus muscles in the upper back when viewed from behind.

Palpation: Localizing the Source of Pain

Following inspection, palpation seeks to identify the precise anatomical source of discomfort and assess tissue quality. Use the pads of your fingers to systematically palpate bones, joints, tendons, and muscle bellies. Key findings include tenderness (point or diffuse), warmth, and crepitus—a grating sensation or sound that can be felt or heard during joint movement, often indicative of cartilage wear or fracture fragments. Begin away from the reported pain and move toward it. In a knee exam, you would palpate the joint line, tibial tubercle, and patellar borders, assessing for tenderness that might suggest meniscal injury or patellofemoral syndrome.

Assessing Range of Motion and Muscle Strength

Evaluating function is critical. Range of motion (ROM) testing assesses joint mobility, both actively (patient moves the joint themselves) and passively (you move the joint for them). A discrepancy—where passive ROM exceeds active ROM—often points to weakness or pain inhibition from tendon/muscle pathology. Measure ROM using a goniometer when precision is needed, comparing to established norms and the uninjured side.

Muscle strength grading provides an objective measure of neuromuscular function. The standard 0–5 scale is:

• 5/5: Normal strength against full resistance.
• 4/5: Active movement against gravity and some resistance, but less than normal.
• 3/5: Active movement against gravity only.
• 2/5: Active movement only with gravity eliminated (e.g., sliding limb on a table).
• 1/5: A visible or palpable muscle contraction without joint movement.
• 0/5: No contraction at all.

Always test strength isometrically (against resistance without joint movement) to isolate specific muscles. For example, testing shoulder abduction strength isolates the supraspinatus.

Evaluating Joint Stability and Gait

Joint stability assessment determines the integrity of ligaments and the joint capsule. This involves applying stress to test for excessive laxity. The Lachman test for the anterior cruciate ligament (ACL) and the anterior drawer test for the ankle are classic examples. Always compare to the unaffected side, as baseline ligamentous laxity varies between individuals.

Gait analysis is an essential part of the lower extremity and spinal exam. Observe the patient walking normally. Note the stance and swing phases. Common pathological gaits include:

• Antalgic gait: A painful, shortened stance phase on the affected side ("limping").
• Trendelenburg gait: The pelvis drops on the side opposite the pathology during single-leg stance, indicating hip abductor weakness.
• Steppage gait: Excessive knee and hip flexion to clear a foot that cannot dorsiflex, seen in peroneal nerve injury.

Provocative Tests and Special Maneuvers

These targeted tests reproduce symptoms or elicit signs to confirm specific pathologies. They are the final, hypothesis-driven step in your exam.

• Rotator Cuff: The Empty Can Test (Jobe’s test) isolates the supraspinatus. With the patient’s arms abducted to 90°, internally rotated (thumbs down), and elevated 30° forward, you apply downward resistance. Pain or weakness suggests a supraspinatus tear or tendinopathy.
• Knee Ligaments: The Lachman Test is the most sensitive for ACL injury. With the knee flexed 20–30°, stabilize the femur and pull the tibia anteriorly. Increased forward translation without a firm endpoint indicates an ACL tear.
• Spine Evaluation: For nerve root irritation (radiculopathy), Straight Leg Raise (SLR) tests the L5/S1 roots. With the patient supine, passively raise the straightened leg. Pain radiating below the knee at 30–70° of elevation suggests sciatic nerve tension. The Femoral Nerve Stretch Test (prone knee bend) assesses L2-L4 roots.

Consider this clinical vignette: A 25-year-old soccer player presents with acute knee pain after a twisting injury. Your inspection reveals a subtle effusion. Palpation finds maximal tenderness along the medial joint line. Active ROM is limited by pain. Strength testing is mostly normal except for discomfort with resisted flexion. Stability testing reveals a positive Lachman test. Your focused exam, integrating all these elements, strongly points toward a combined injury: a medial meniscus tear and an ACL rupture.

Common Pitfalls

1. Skipping the Unaffected Side: Failing to examine the contralateral limb for comparison is a critical error. You cannot interpret subtle swelling, laxity, or limited ROM without knowing the patient's normal baseline.
2. Poor Palpation Technique: Using fingertips instead of finger pads, or palpating too deeply initially, can cause unnecessary pain and muscle guarding, obscuring accurate findings. Always start gently and superficially.
3. Over-relying on Special Tests: Performing provocative maneuvers without first completing inspection, palpation, and basic ROM/strength testing is putting the cart before the horse. Special tests are for confirmation, not screening. A positive test may be misleading if the anatomy hasn't been systematically assessed.
4. Ignoring Functional Assessment: Documenting "strength 5/5" is insufficient if the patient cannot climb onto the exam table due to pain. Always contextualize your isolated findings with a simple functional question, like "Can you walk up stairs?" or "Can you lift your arm to brush your hair?"

Summary

• The musculoskeletal exam follows a logical sequence: Inspect, Palpate, Move (assess ROM and strength), and then perform Stability tests and Special Maneuvers.
• Palpation identifies precise anatomical tenderness and crepitus, while muscle strength grading provides an objective 0–5 scale for documenting weakness.
• Joint stability tests (e.g., Lachman) assess ligaments, and observing gait reveals critical functional deficits in the lower limb and spine.
• Provocative tests like the Empty Can test for the rotator cuff or Straight Leg Raise for the spine are used to confirm specific pathologies after forming a diagnostic hypothesis from earlier exam steps.
• Always compare to the unaffected side and integrate findings into a coherent clinical story that explains the patient's symptoms and functional limitations.