Anatomy, Physiology and Biomechanics
What you must be able to reconstruct
Build a mental map of the musculoskeletal, peripheral nerve and vascular anatomy that underpins every technique you perform. Know muscle attachments, actions and nerve supply well enough to predict which movement a lesion abolishes. For the shoulder, know that supraspinatus initiates abduction, deltoid sustains it, and the rotator cuff provides dynamic stability. For the hip, distinguish gluteus medius (abduction, pelvic drop on the swing side in Trendelenburg) from gluteus maximus (extension). For the knee, know the screw-home mechanism and the role of the quadriceps angle.
Physiology: understand the length-tension relationship, the force-velocity curve, and the difference between active and passive insufficiency. Know muscle fibre types and their fatigue profiles, and the physiology of pain transmission (nociceptors, dorsal horn, descending inhibition) because it explains why exercise and manual therapy modulate pain.
Biomechanics: levers, moment arms, torque, and the effect of posture on joint loading. Understand open versus closed kinetic chain exercise and the implications for shear versus compression. Know spinal coupling and the neutral zone concept.
Traps
Questions often swap nerve roots (e.g., foot dorsiflexion is L4-L5, not L5-S1), or describe a muscle action in a closed chain where the action reverses. Watch for questions asking which muscle is stretched rather than active. Another trap is confusing the direction of pelvic rotation with hip motion.
Rule of thumb
For any joint, ask: which muscle produces this movement, what nerve supplies it, and which root? If you can answer all three, most anatomy items resolve. Example: hip abduction - gluteus medius - superior gluteal nerve - L4-L5-S1.