13.1 Kinesiology, Biomechanics & Functional Anatomy

ABPMR Physical Medicine and Rehabilitation Board Exam Study Guide Exam

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1 Chapter 1: Introduction & Exam Overview

1.1 ABPMR Part I Exam Overview & Format 1.2 Board Review Strategy & Content Blueprint Breakdown

2 Chapter 2: Musculoskeletal Medicine

2.1 Shoulder & Upper Extremity Diagnostics 2.2 Knee, Hip & Lower Extremity Conditions 2.3 Spine Pathology, Radiculopathy & Myelopathy 2.4 Inflammatory Arthritis, Tendinopathies & Concussion 2.5 Bone Health, Osteoporosis & Metabolic Bone Disease 2.6 Thoracic Outlet Syndrome & Peripheral Nerve Entrapment 2.7 Fracture Rehabilitation & Immobilization Complications 2.8 Overuse Tendinopathies & Regenerative Medicine 2.9 Gait Analysis & Abnormal Gait Patterns

3 Chapter 3: Spinal Cord Injury Rehabilitation

3.1 ASIA Examination & Impairment Scale 3.2 Spinal Cord Injury Syndromes 3.3 Autonomic Dysreflexia & Acute Complications 3.4 Neurogenic Bladder, Bowel & Secondary Complications

4 Chapter 4: Stroke & Neuromuscular Rehabilitation

4.1 Stroke Vascular Syndromes & Acute Assessment 4.2 Stroke Motor Recovery & Hemiplegic Complications 4.3 Spasticity Assessment & Multimodal Management 4.4 ALS, GBS, CIDP & Neuromuscular Disease Rehab 4.5 Multiple Sclerosis & Demyelinating Disease Rehabilitation 4.6 Parkinsonism, Movement Disorders & Functional Neurologic Disorder

5 Chapter 5: Electrodiagnostics (EMG/NCS)

5.1 Nerve Conduction Studies Principles & Physics 5.2 Needle Electromyography & MUAP Analysis 5.3 Mononeuropathies & Radiculopathy Patterns 5.4 Neuromuscular Junction Disorders & Myopathies

6 Chapter 6: Traumatic Brain Injury

6.1 TBI Severity Classification, Glasgow Coma Scale, and Pathophysiology 6.2 Rancho Los Amigos Levels of Cognitive Functioning and Disability Rating Scale 6.3 Neurobehavioral Sequelae and Agitation Management 6.4 Concussion Evaluation, Vestibular-Ocular Dysfunction, and Return-to-Play/Work Protocols

7 Chapter 7: Chronic Pain & Interventional Spine

7.1 Fluoroscopic Spine Interventions 7.2 Opioid Stewardship & Controlled Substance Compliance 7.3 Complex Regional Pain Syndrome, Fibromyalgia & Myofascial Pain 7.4 Spinal Cord Stimulation & Intrathecal Therapy

8 Chapter 8: Amputee Rehabilitation & Prosthetics

8.1 Amputation Surgical Levels & Medicare K-Levels 8.2 Socket Designs & Suspension Systems 8.3 Prosthetic Feet & Microprocessor Knee Mechanisms 8.4 Post-Amputation Care, Residual Limb & Phantom Pain

9 Chapter 9: Pediatric Rehabilitation

9.1 Cerebral Palsy Classification & GMFCS 9.2 Spina Bifida & Myelomeningocele Management 9.3 Muscular Dystrophies & Neuromuscular Disease in Children 9.4 Pediatric Brachial Plexopathy & Congenital Disorders

10 Chapter 10: Prosthetics, Orthotics & Assistive Technology

10.1 Lower Limb Orthoses — AFOs & KAFOs 10.2 Spinal & Upper Extremity Orthoses 10.3 Upper Limb Prosthetics — Body-Powered vs Myoelectric 10.4 Wheelchairs, Seating Systems & Pressure Mapping

11 Chapter 11: Medical Rehabilitation & Outcomes

11.1 Dysphagia Assessment & Management 11.2 Neurogenic Bladder & Bowel Management 11.3 Pressure Injuries & Wound Management 11.4 Outcome Measures & Medical Complications 11.5 Cancer Rehabilitation & Oncologic Rehabilitation 11.6 Burns, Endocrine/Metabolic & Medical Complications Rehabilitation

12 Chapter 12: Cardiopulmonary Rehabilitation

12.1 Cardiac Rehabilitation Phases & Metabolic Equivalents 12.2 Pulmonary Rehabilitation & COPD Management

13 Chapter 13: Foundational Rehabilitation Concepts

13.1 Kinesiology, Biomechanics & Functional Anatomy 13.2 Rehabilitation Pharmacology & Medication Management 13.3 Research Methodology, Biostatistics & Evidence-Based Practice 13.4 Nutrition, Metabolism & Energy Expenditure in Rehabilitation 13.5 Diagnostic Procedures: Imaging, MSK Ultrasound, Urodynamics & Neuropsych Assessment

13.1 Kinesiology, Biomechanics & Functional Anatomy

Key Takeaways Explain This Topic AI

Kinesiology studies human movement; biomechanics applies mechanics (statics and dynamics) to the musculoskeletal system—forces, moments, levers, and joint reaction forces that underpin rehabilitation prescription.

Muscle actions include concentric (shortening, acceleration), eccentric (lengthening, deceleration), and isometric (no length change, stabilization); eccentric contractions generate the highest force at lowest metabolic cost but carry the greatest injury risk.

A muscle's force output depends on length-tension (optimal at resting length) and force-velocity (force falls as shortening velocity rises; rises during eccentric) relationships.

Lever systems in the body are predominantly third-class (effort between fulcrum and load), favoring speed and range of motion at the cost of force; the elbow flexors are the classic example.

Last updated: July 2026

Kinesiology, Biomechanics & Functional Anatomy

Kinesiology and biomechanics are Domain A applied-science foundations. Understanding forces, moments, levers, and muscle physiology lets the physiatrist prescribe exercise, analyze gait, design orthoses, and prevent injury.

Forces, Moments, and Joint Reaction Force

Force (Newton): a push or pull; vector with magnitude and direction.

Moment (torque) : force x perpendicular distance from the axis of rotation; the rotary component that moves joints.

Joint reaction force : the net internal force at a joint surface, often several times body weight because muscles must counter external moments. External Moment = (External Force) x (Moment Arm)

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└──► Internal Muscle Force Must Balance It
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└──► Joint Reaction Force (frequently 2-4x body weight at the hip/knee)

Because muscle moment arms are short relative to external loads, muscle forces and joint reaction forces are large. This explains why the hip joint reaction force during gait is ~2.5-3x body weight and why a contralateral cane (long external moment arm) reduces required abductor force and joint reaction force.

Muscle Contraction Types

Type Length Change Function Force / Risk
Concentric Shortening Acceleration, lifting Moderate; lowest max force

Eccentric Lengthening Deceleration, controlled lowering Highest force, lowest metabolic cost; highest injury risk

Isometric No change Stabilization, posture Moderate; useful when ROM limited

Eccentric loading underpins both tendinopathy rehab (controlled lengthening) and the higher rate of muscle strain injury (e.g., hamstring during sprint deceleration).

Length-Tension & Force-Velocity Relationships

Length-tension : peak active force at near-resting sarcomere length; too short or too stretched reduces cross-bridge overlap and force (active component); passive tension rises at long lengths.

Force-velocity : concentric force decreases as shortening velocity increases; eccentric force increases with velocity up to a plateau; isometric is the reference. These guide exercise tempo and loading choices.

Lever Systems

Class Fulcrum-Effort-Load Body Example Functional Trade
1st Fulcrum between Neck extension (atlanto-occipital), triceps on ulna Balance
2nd Load between fulcrum and effort Calf raising on the forefoot (toes fulcrum, body load) Force advantage
3rd Effort between fulcrum and load Elbow flexors (biceps/brachialis) Speed/ROM advantage (most common)

The predominance of third-class levers explains why muscles generate large forces (small moment arm) to overcome external loads at long moment arms—the musculoskeletal system is built for speed and range of motion, not mechanical advantage.

Functional Anatomy Applications

Glenohumeral mobility-stability trade-off (rotator cuff and scapular stabilizers).

Lumbopelvic load transfer (core stability, multifidus, transversus abdominis).

Kinetic chains : open vs closed kinetic chain exercise change joint forces and muscle activation (e.g., closed-chain favored early after ACL reconstruction to reduce anterior tibial translation).

This foundation recurs throughout orthotic, prosthetic, and gait prescriptions in the guide.

Kinetic Chains: Open vs Closed

Kinetic Chain Characteristic Rehab Example
Open (OKC) Distal segment free; isolated joint loading Knee extension quad sets, leg curls
Closed (CKC) Distal segment fixed; multi-joint, compressive Squat, leg press, wall sits

Closed-chain exercise reduces shear at the knee (e.g., preferred early after ACL reconstruction, reducing anterior tibial translation) and recruits co-contraction for stability; open-chain isolates muscles and is useful for targeted strengthening. Selection depends on healing stage, joint stability, and goal.

Core Stability & Lumbopelvic Mechanics

Trunk stability is generated by coordinated activation of transversus abdominis, multifidus, diaphragm, and pelvic floor—"core stability" transfers loads between upper and lower extremities while protecting the spine. Impairment (deconditioning, post-surgical, low back pain) leads to aberrant movement and injury. Rehabilitation emphasizes motor control and endurance before pure strength, integrating breathing and bracing into functional tasks.

Biomechanics of Common Rehab Interventions

Stretching : sustained stretch elicits viscoelastic deformation and (over time) tissue remodeling; static stretching > 30 s improves ROM; PNF (contract-relax) uses autogenic inhibition.

Resistance : progressive overload increases strength through neural adaptation (early) and hypertrophy (later); tendon, bone, and ligament remodel to load.

Proprioception/balance : sensory reweighting reduces falls; relevant to ankle instability, vestibular, and geriatric rehab.

Gait and transfer training : applies moment and lever principles to minimize joint loading and energy cost.

Worked Example: Cane Biomechanics

A 70 kg patient with right hip OA uses a cane in the left hand generating 100 N downward force at a 0.5 m moment arm from the right hip; body weight (~700 N) acts at ~0.1 m from the hip center. The cane's counter-moment reduces the required abductor force and the joint reaction force substantially—illustrating how a simple assistive device leverages biomechanics. Candidates should reason qualitatively about moments and forces rather than memorize numbers, applying the lever and joint-reaction-force principles to orthotic, prosthetic, and assistive-device questions.