3.6 Bones, Muscles & Joints of the Arms, Hands, Legs & Feet

Arizona Cosmetology Licensing Exam Study Guide Exam

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1 Chapter 1: Arizona Cosmetology Licensing & Board Regulations

1.1 The Arizona Barbering and Cosmetology Board & Licensing Routes 1.2 The Two Arizona Examinations, Scoring & Fees 1.3 License Renewal, Display, Inactive Status & Reactivation 1.4 Establishments, Inspections, Scope of Practice & Discipline

2 Chapter 2: Infection Control, Safety & First Aid Standards

2.1 Principles of Microbiology & Pathogens 2.2 Decontamination Levels: Cleaning, Disinfection & Sterilization 2.3 OSHA Safety Standards & SDS Compliance 2.4 Blood Exposure Protocols & First Aid Emergencies 2.5 Arizona Infection Control Standards in Daily Practice

3 Chapter 3: Human Anatomy, Physiology & Chemistry

3.1 Integumentary System & Skin Anatomy 3.2 Trichology: Hair Structure, Growth & Disorders 3.3 Nail Anatomy, Physiology & Pathology 3.4 Basics of Chemistry & pH Scale 3.5 Muscles of the Head, Face & Neck 3.6 Bones, Muscles & Joints of the Arms, Hands, Legs & Feet 3.7 The Nervous System in Cosmetology 3.8 The Circulatory & Lymphatic Systems

4 Chapter 4: Haircare, Haircutting & Styling Principles

4.1 Hair & Scalp Analysis 4.2 Principles of Haircutting & Elevation 4.3 Wet & Thermal Hair Styling 4.4 Wigs, Hair Additions & Natural Hair Styling 4.5 Hair Care Tools, Electrical Equipment & Safe Handling 4.6 Draping, Shampooing, Conditioning & Scalp Treatments 4.7 Haircutting Implements in Practice & Cutting Techniques 4.8 Hair Design Principles: Face Shapes, Balance & Proportion 4.9 Textured Hair: Curl Patterns, Care & Service Adaptations

5 Chapter 5: Chemical Texture Services

5.1 Chemistry of Perming & Disulfide Bonds 5.2 Permanent Waving Techniques & Wrap Patterns 5.3 Chemical Hair Relaxers & Hydroxide Chemistry 5.4 Keratin Smoothing & Chemical Reforming Procedures

6 Chapter 6: Haircolor & Hair Lightening Services

6.1 Color Theory & Natural Hair Pigment 6.2 Haircolor Classifications & Developers 6.3 Hair Lightening & Decolorizing Services 6.4 Consultation, Predisposition Testing & Color Corrections

7 Chapter 7: Skin Care, Facials & Hair Removal Services

7.1 Skin Analysis, Typing & Conditions 7.2 Facial Treatment Procedures & Cleansing 7.3 Hair Removal Services & Epilation Methods 7.4 Electrotherapy, Facial Machines & Cosmetic Makeup 7.5 Lash & Brow Services and Arizona Eyelash Rules

8 Chapter 8: Nail Care, Manicuring & Nail Enhancements

8.1 Basic Manicure & Pedicure Procedures 8.2 Nail Disorders, Diseases & Safety Contraindications 8.3 Monomer Liquid & Polymer Powder Nail Enhancements 8.4 Light-Cured Gels, Wraps & Electric Filing Safety 8.5 Nail Tools, Equipment & Arizona Foot Spa Disinfection

9 Chapter 9: Salon Business Management, Ethics & Career Practices

9.1 Salon Ownership, Business Structures & Regulations 9.2 Financial Management, Pricing & Retail Sales 9.3 Employment Classification & Tax Compliance 9.4 Professional Ethics, Communication & Client Retention

3.6 Bones, Muscles & Joints of the Arms, Hands, Legs & Feet

Key Takeaways Explain This Topic AI

The arm has one upper bone, the humerus, and two forearm bones: the ulna on the little-finger side and the radius on the thumb side.

Each hand contains 27 bones — 8 carpals in the wrist, 5 metacarpals in the palm, and 14 phalanges in the digits.

Pronators turn the hand palm-down and supinators turn it palm-up; flexors bend the wrist and close the fingers while extensors straighten them, and abductors separate the fingers while adductors draw them together.

Each foot contains 26 bones — 7 tarsals, 5 metatarsals, and 14 phalanges — with the talus, calcaneus, navicular, cuboid, and three cuneiforms making up the tarsal group.

The tibialis anterior lifts the foot and turns it inward, the gastrocnemius and soleus flex the foot downward, and the peroneus longus and brevis evert the foot and turn it outward.

Last updated: August 2026

Where This Shows Up in Practice

A manicure includes hand and arm massage; a pedicure includes foot and lower-leg massage. Both are listed in the NIC content outlines under nail care principles and procedures, and both require you to know which structures tolerate pressure and which do not. Pressing directly on the carpals of a client with carpal tunnel syndrome, or working aggressively over the medial malleolus of a diabetic client, converts a relaxing service into an injury.

Bones of the Shoulder, Arm, and Hand

Bone Location Notes
Clavicle Collarbone; joins sternum to scapula Superficial and easily bruised
Scapula Shoulder blade Controlled by the trapezius
Humerus Uppermost and largest bone of the upper arm One bone only
Ulna Inner forearm bone, on the little-finger side Its upper end forms the point of the elbow
Radius Outer forearm bone, on the thumb side Rotates over the ulna in pronation
Carpals 8 small irregular bones of the wrist Held together by ligaments
Metacarpals 5 long slender bones of the palm One per digit
Phalanges 14 bones of the digits — three per finger, two in the thumb Singular: phalanx

Total bones in the hand and wrist: 8 + 5 + 14 = 27.

Muscles of the Arm and Hand

The muscles fall into functional pairs, and the exam tests the pair relationships more than individual names.

Group Action Example
Flexors Bend the wrist, draw the hand up, close the fingers Flexor digitorum
Extensors Straighten the wrist, hand, and fingers Extensor digitorum
Pronators Turn the hand palm downward Pronator teres
Supinators Turn the hand palm upward Supinator
Abductors Separate the fingers Abductor digiti minimi
Adductors Draw the fingers together Adductor pollicis

A memory hook that survives exam pressure: ab ductors move away , ad ductors add the fingers back together. Abductors and adductors are located at the base of each digit.

Three upper-arm muscles complete the set:

Biceps — the two-headed muscle at the front of the upper arm; lifts the forearm and flexes the elbow .

Triceps — the three-headed muscle covering the entire back of the upper arm; extends the forearm .

Deltoid — large triangular muscle covering the shoulder joint; lifts and turns the arm .

Bones of the Lower Leg and Foot

Bone Location
Femur Thigh — the longest bone in the body
Patella Kneecap
Tibia Larger, inner shin bone; forms the medial malleolus at the ankle
Fibula Smaller, outer lower-leg bone; forms the lateral malleolus
Tarsals 7 ankle bones: talus, calcaneus (heel), navicular, cuboid, and three cuneiforms
Metatarsals 5 long bones of the instep
Phalanges 14 toe bones — three per toe, two in the great toe

Total bones in the foot: 7 + 5 + 14 = 26. Contrast this with the 27 in the hand and wrist — the two counts are a favorite distractor pair.

Muscles of the Lower Leg and Foot

Muscle Action Massage Relevance

Tibialis anterior Covers the front of the shin; lifts the foot and turns it inward Often tender in clients who stand all day

Gastrocnemius Superficial calf muscle; flexes the foot downward (plantar flexion) The bulk of the calf massage
Soleus Beneath the gastrocnemius; bends the foot down Deeper, slower pressure
Peroneus longus Covers the outer side of the calf; everts the foot and turns it outward Runs along the fibula

Peroneus brevis Originates on the lower fibula; everts the foot and turns it outward Works with peroneus longus

Extensor digitorum longus Front of the leg; bends the foot up and extends the toes Superficial over the instep

Flexor digitorum brevis Sole of the foot; moves the toes and helps maintain balance The plantar surface worked in pedicure massage

Abductor and adductor hallucis Move and stabilize the great toe Relevant to bunion-prone clients
Joints and Safe Pressure

A joint is where two or more bones meet. Cosmetologists work over hinge joints (elbow, knee, interphalangeal joints of the fingers and toes) and gliding joints (carpals, tarsals). Two working rules follow:

Never force a joint through its range of motion. Rotation during hand or foot massage is passive and gentle; the client's own tissue sets the limit.

Never apply deep pressure directly over a bony prominence — the malleoli at the ankle, the olecranon at the elbow, the metacarpal and metatarsal heads. Work the muscle bellies around them.

For clients with diabetes mellitus , peripheral neuropathy, or peripheral arterial disease, reduce pressure further and stop at the first sign of skin change. Section 8.5 covers the full contraindication set for foot services.