MSk
Musculoskeletal Assessment for Nurse Practitioners
Comprehensive study guide for advanced health assessment and NP certification exam preparation.
Focuses on high-yield musculoskeletal examination techniques, diagnostic maneuvers, and clinical decision-making for common orthopedic conditions across the lifespan.
Knee Examination: Essential Special Tests
Ligamentous Stability Tests
Anterior Drawer Test:
Purpose: Assesses anterior cruciate ligament (ACL) integrity.
Technique: With the knee flexed at 90°, pull tibia forward.
Positive Test: Excessive anterior translation compared to the opposite knee indicates ACL tear.
Lachman Test:
Purpose: More sensitive test for ACL injury.
Technique: Knee flexed at 20-30°, stabilize femur and pull tibia anteriorly.
Positive Test: Soft or absent endpoint suggests ACL injury; considered the gold standard for ACL assessment.
Posterior Drawer Test:
Purpose: Evaluates posterior cruciate ligament (PCL).
Technique: Push tibia posteriorly with the knee at 90°.
Positive Test: Excessive posterior movement indicates PCL rupture.
Meniscal Injury Tests
McMurray Test:
Purpose: Detects meniscal tears.
Technique: Flex the knee maximally, externally rotate tibia and extend knee for medial meniscus; internally rotate for lateral meniscus.
Positive Test: Palpable click or pop with pain suggests a tear.
Apley Compression Test:
Purpose: Distinguishes meniscal pathology from ligamentous injury.
Technique: Patient prone, knee flexed at 90°. Apply downward pressure while rotating tibia.
Positive Test: Pain indicates meniscal injury.
Bulge Sign (Ballottement):
Purpose: Assesses for knee effusion.
Technique: Stroke medial side of the knee upward, then tap lateral side.
Positive Test: Fluid wave returning to the medial side confirms small effusion; critical for early joint inflammation detection.
Hip Assessment and Pediatric Conditions
Legg-Calvé-Perthes Disease
Age: 4-8 years, male predominance (4:1).
Presentation: Insidious limp, hip/knee pain, limited abduction and internal rotation.
Pathophysiology: Avascular necrosis of the femoral head.
Exam Findings: Antalgic gait, decreased range of motion (ROM), especially abduction.
Action: Requires orthopedic referral and imaging; X-ray shows femoral head flattening.
Slipped Capital Femoral Epiphysis (SCFE)
Age: 10-16 years, often in obese adolescents.
Presentation: Hip, thigh, or knee pain; limping.
Key Finding: Affected leg externally rotated and shortened; limited internal rotation and flexion.
Emergency: Acute slips require immediate orthopedic referral to prevent avascular necrosis; X-ray shows posterior/inferior displacement of the femoral epiphysis.
Osgood-Schlatter Disease
Age: Active adolescents 10-15 years during growth spurts.
Presentation: Anterior knee pain over tibial tuberosity, worsened by running, jumping, kneeling.
Exam Findings: Tenderness, prominent tibial tubercle; pain with resisted knee extension.
Management: Usually self-limiting; treatment includes rest, ice, NSAIDs, quadriceps stretching; resolves with skeletal maturity.
Pediatric Lower Extremity Alignment
Genu Varum (Bowlegs)
Definition: Outward bowing of legs with knees apart when ankles together.
Normal Range: Birth to 18-24 months due to intrauterine positioning.
Concerning Findings:
Persistence beyond age 2,
Unilateral bowing,
Worsening deformity,
Intercondylar distance >6cm suggests pathologic causes (e.g., Blount disease, rickets).
Referral: If asymmetric, progressive, or beyond normal age range.
Genu Valgum (Knock-Knees)
Definition: Inward angulation with knees touching, ankles apart.
Normal Range: Peaks at ages 3-4 years; gradually resolves by age 7-8.
Concerning Findings:
Intermalleolar distance >8cm,
Asymmetry,
Pain,
Persistence beyond age 8 years.
Assessment: Measure distance between medial malleoli with knees together and monitor growth curves.
Pediatric Gait Development
12-15 months: Wide-based gait, arms in high guard position, feet flat.
18 months: Narrower base, initiation of reciprocal arm swing.
2-3 years: Mature heel-to-toe pattern emerges; improved balance.
4 years: Adult-like gait pattern established.
Red Flags: Persistent toe-walking beyond age 2, asymmetric gait, regression of milestones require further evaluation.
Scoliosis Screening and Assessment
Screening Importance
Essential during adolescence, particularly for girls ages 10-14 during peak growth velocity.
Adams Forward Bend Test
Standard Screening Maneuver: Reveals rib humps or paraspinal prominences indicative of vertebral rotation.
Visual Inspection
Patient standing for assessment:
Shoulder height symmetry,
Scapular prominence,
Waist crease asymmetry,
Overall spinal alignment.
Note any obvious lateral curvature or trunk shift.
Scoliometer Measurement
Technique: Place scoliometer across apex of rib hump or paraspinal prominence during forward bend.
Readings: ≥7° angle of trunk rotation (ATR) warrants orthopedic referral and radiographic evaluation; document measurement location (thoracic vs. lumbar).
Referral Needs
Refer if:
ATR ≥7°,
Rapidly progressive curve,
Presence of pain (suggests non-idiopathic causes),
Neurological findings,
Curve noted before age 8.
Confirmation: Cobb angle >10° on X-ray confirms scoliosis diagnosis.
Juvenile Idiopathic Arthritis and Gower Sign
Juvenile Idiopathic Arthritis (JIA)
Definition: Most common chronic rheumatic disease in children, onset before age 16.
Presentation: Joint swelling, morning stiffness lasting >15 minutes, decreased ROM, warmth without erythema; systemic symptoms may include fever, rash, lymphadenopathy.
Exam Findings: Boggy joint swelling, limited ROM, growth disturbances, leg length discrepancy.
Action: Immediate rheumatology referral for diagnosis, initiation of DMARDs, and monitoring; uveitis screening is essential.
Gower Sign
Classic Indicator: Proximal muscle weakness, indicative of muscular dystrophy (e.g., Duchenne).
Behavior: Child