The musculoskeletal system is composed of bones, muscles, and joints.
It is controlled and innervated by the nervous system.
Its overall purpose is to provide structure and movement for body parts.
Bones
Bones provide structure and protection.
They serve as levers.
They store calcium.
They produce blood cells.
There are a total of 206 bones in the body.
These bones make up the axial skeleton (head and trunk) and the appendicular skeleton
Bones are made of osseous tissue, and are classified as:
Compact (dense, forms shafts and outer layers).
Spongy (porous, found at ends and centers).
Osteoblasts build bone.
Osteoclasts break down bone.
Red marrow produces blood cells.
Yellow marrow stores fat.
The periosteum (covering bones) contains blood vessels and osteoblasts for nourishment and growth.
Bone shapes:
Short (carpals).
Long (humerus, femur).
Flat (sternum, ribs).
Irregular (hips, vertebrae).
Skeletal Muscles
The body has three muscle types: skeletal, smooth, and cardiac.
The musculoskeletal system includes 650 skeletal (voluntary) muscles.
Skeletal muscles are controlled consciously.
They are made of bundled muscle fibers (fasciculi) bound by connective tissue.
Skeletal muscles connect to bones via tendons, helping with posture, movement, and heat production.
Anatomical Movements
Abduction: Moving away from the midline of the body.
Adduction: Moving towards the midline of the body.
Circumduction: Circular motion.
Inversion: Moving inward.
Eversion: Moving outward.
Extension: Straightening the extremity at the joint and increasing the angle of the joint.
Hyperextension: Joint bends greater than 180 degrees.
Flexion: Bending the extremity at the joint and decreasing the angle of the joint.
Dorsiflexion: Toes draw upward to ankle.
Plantar flexion: Toes point away from ankle.
Pronation: Turning or facing downward.
Supination: Turning or facing upward.
Protraction: Moving forward.
Retraction: Moving backward.
Rotation: Turning of a bone on its own long axis.
Internal rotation: Turning of a bone toward the center of the body.
External rotation: Turning of a bone away from the center of the body.
Joints
Joints are where two or more bones meet, allowing various ranges of motion.
Joints are classified as fibrous, cartilaginous, or synovial.
Fibrous joints (e.g., skull sutures) are immovable and connected by fibrous tissue.
Cartilaginous joints (e.g., between vertebrae) are joined by cartilage.
Synovial joints (e.g., shoulders, knees) have a fluid-filled space for smooth movement.
Synovial joints are held by ligaments.
Synovial joints are enclosed in a fibrous capsule.
Synovial joints are protected by articular cartilage.
Major Joints
Temporomandibular:
Articulation between the temporal bone and mandible.
Motions: Opens and closes mouth, projects and retracts jaw, moves jaw from side to side.
Elbow:
Articulation between the ulna and radius of the lower arm and the humerus of the upper arm; contains a synovial membrane and several bursae.
Motions: Flexion and extension of the forearm, supination and pronation of the forearm.
Sternoclavicular:
Junction between the manubrium of the sternum and the clavicle, has no obvious movements
Shoulder:
Articulation of the head of the humerus in the glenoid cavity of the scapula. The acromioclavicular joint includes the clavicle and acromion process of the scapula. Contains the subacromial and subscapular bursae.
Motions: Flexion and extension, abduction and adduction, circumduction, rotation (internal and external).
Wrist, Fingers, Thumb:
Articulation between the distal radius, ulnar bone, carpals, and metacarpals. It contains ligaments and is lined with a synovial membrane.
Motions:
Wrists: Flexion, extension, hyperextension, adduction, radial and ulnar deviation.
Fingers: Flexion, extension, hyperextension, abduction, and circumduction.
Thumb: Flexion, extension, and opposition.
Vertebrae:
Thirty-three bones: 7 concave-shaped cervical (C), 12 convex-shaped thoracic (T), 5 concave-shaped lumbar (L), 5 sacral (S), and 3–4 coccygeal, connected in a vertical column.
Bones are cushioned by elastic fibrocartilaginous plates (intervertebral discs) that provide flexibility and posture to the spine.
Paravertebral muscles are positioned on both sides of vertebrae.
Hip:
Articulation between the head of the femur and the acetabulum; contains a fibrous capsule.
Motions: Flexion (with knee flexed and with knee extended), extension and hyperextension, circumduction, and rotation (internal and external), abduction.
Knee:
Articulation of the femur, tibia, and patella; contains fibrocartilaginous disks (medial and lateral menisci) and many bursae.
Motions: Flexion and extension.
Ankle and Foot:
Articulation between the talus (large posterior foot tarsal), tibia, and fibula. The talus also articulates with the navicular bones. The heel (calcaneus bone) is connected to the tibia and fibula by ligaments.
Motions:
Ankle: Plantar flexion and dorsiflexion.
Foot: Inversion and eversion.
Toes: Flexion, extension, abduction, adduction.
Cultural Variations
Bone and muscle structures vary biologically across populations. For example, Blacks tend to have thicker frontal bones, while Whites have thicker parietal bones.
Differences also exist in the lengths of the radius and ulna.
Most people have 24 vertebrae, but 11% of African American women have 24, and 12% of Eskimo and Native American men have 25
According to the CDC (2019), arthritis prevalence in 2015 was highest among non-Hispanic Whites (41.3 million), followed by non-Hispanic Blacks (6.1 million), Hispanics (4.4 million), and non-Hispanic Asians (1.5 million).
Additionally, 26% of women and 19.1% of men reported doctor-diagnosed arthritis.
Assessing Subjectively
Assessing the musculoskeletal system helps determine a client's ability to perform activities of daily living (ADLs).
Since this system affects the whole body, only the client can describe symptoms like pain, stiffness, and movement limitations.
Nutritional habits, activity levels, and exercise are also key parts of the assessment. A pain assessment may be needed, as pain is a common concern.
Because the neurologic system coordinates muscle and skeletal function, understanding their connection is important.
This assessment gives insight into daily habits that impact musculoskeletal health.
Client education on exercise, diet, posture, and safety is a vital part of care.
History of Present Health Concern
Weight gain can increase physical stress and strain on the musculoskeletal system.
Clients with temporomandibular joint (TMJ) dysfunction may have difficulty chewing and may describe their jaws as “getting locked or stuck.” Jaw tenderness, pain, or a clicking sound may also be present with TMJ
Bone pain is typically dull, deep, and throbbing, while joint or muscle pain feels more like aching and can be mechanical or inflammatory in nature. Fracture pain is sharp, knifelike, and worsens with movement.
Osteoarthritis often starts in one joint or one side, with deep joint pain that improves with rest but worsens in rainy weather, often with morning stiffness that eases with movement.
Rheumatoid arthritis usually causes burning or throbbing pain on both sides of the body, worsens after inactivity, and comes with symptoms like joint heat, fatigue, weight loss, morning stiffness lasting over an hour, and possible low-grade fever or swollen glands.
Fibromyalgia is marked by widespread pain, fatigue, memory issues, and mood changes. It’s hard to diagnose and often linked to genetics or triggers like trauma or infections. It affects more women and those with a family history or rheumatic conditions. Diagnosis is based on widespread pain lasting over three months with no clear cause, supported by tests like CBC, sedimentation rate, and thyroid function.
Personal Health History
Past injuries may affect the client’s current ROM and level of function in affected joints and extremities.
A history of recurrent fractures may be seen with osteomalacia but should also raise the question of possible physical abuse
Joint stiffening and other musculoskeletal symptoms may be a transient effect of the tetanus, whooping cough, diphtheria, or polio vaccines
Conditions like diabetes mellitus, sickle cell anemia, and SLE increase the risk of musculoskeletal issues such as osteoporosis and osteomyelitis. Type 1 diabetes is linked to low bone density and higher fracture risk, often due to vision and nerve damage leading to falls. Though type 2 diabetes may come with higher bone density due to weight, fracture risk remains high for similar reasons. Clients who are immobile or have low calcium and vitamin D intake are also more prone to developing osteoporosis.
Women who begin menarche late or begin menopause early are at greater risk for development of osteoporosis because of decreased estrogen levels, which tend to decrease the density of bone mass
Family History
Rheumatoid arthritis, gout, and osteoporosis tend to be familial and can increase the client’s risk for development of these diseases.
Lifestyle and Health Practices
Adequate protein supports muscle tone and bone growth, while vitamin C aids tissue and bone healing. Calcium deficiency raises osteoporosis risk, and vitamin D is needed for calcium absorption. Recommended vitamin D intake ranges from 400-1,000 IU daily, with a safe upper limit of 4,000 IU for most adults. Diets high in purines (like meat, liver, sardines) and alcohol can trigger gouty arthritis.
A sedentary lifestyle increases the risk of osteoporosis. Prolonged immobility leads to muscle atrophy. Exposure to 20 minutes of sunlight per day promotes the production of vitamin D in the body. Vitamin D deficiency can cause osteomalacia and limit calcium absorption
Regular exercise improves flexibility, muscle tone, and strength. Only weight-bearing exercises can boost bone density. Exercise also helps slow age-related bone loss (osteopenia/osteoporosis) and muscle degeneration (sarcopenia). Poor body positioning in contact sports can lead to bone, joint, or muscle injuries.
Poor body mechanics, heavy lifting, and bad posture can cause back problems, while repetitive wrist and hand movements may lead to carpal tunnel syndrome.
Poor posture, prolonged forward bending (as in sitting) or backward leaning (as in working overhead), or long-term carrying of heavy objects on the shoulders can result in back problems. Contracture of the Achilles tendon can occur with prolonged use of high-heeled shoes.
Impairment of the musculoskeletal system may impair the client’s ability to perform normal ADLs. Correct use of assistive devices can promote safety and independence. Some clients may feel embarrassed and not use their prescribed or needed assistive device
Musculoskeletal problems, especially chronic ones, can disable and cripple the client, which may impair socialization and prevent the client from performing the same roles as in the past. Back problems, joint pain, or muscle stiffness may interfere with sexual activities.
Body image disturbances and chronic low self-esteem may occur with a disabling or crippling problem
Musculoskeletal problems often greatly affect ADLs and role performance, resulting in changed relationships and increased stress
The U.S. Preventive Services Task Force (USPSTF, 2018) recommends that postmenopausal women younger than age 65 get bone density scans if they have risk factors for osteoporosis, including a history of fractured bones, being White, smoking, alcohol abuse, or a slender frame. Bone density screening is recommended for all women at age 65. The USPSTF recommended against screening for men.
Assessing Objectively
Physical assessment of the musculoskeletal system provides data regarding the client’s posture, gait, bone structure, muscle strength, and joint mobility, as well as the client’s ability to perform ADLs. The physical assessment includes inspecting and palpating the joints, muscles, and bones; testing ROM; and assessing muscle strength.
Preparing the Client
Since the exam is lengthy, ensure the room is comfortable and offer rest as needed. Use proper draping to maintain privacy while allowing visibility of the area being assessed. Explain that the client will need to change positions and move body parts against resistance and gravity. Give clear, simple instructions and demonstrate movements to guide the client during the exam.
Equipment
Tape measure
Goniometer
Skin marking pen
Inspection - Posture
Posture is erect and comfortable for age.
Slumped shoulders may result from poor posture (especially while seated) or from depression.
Abnormal curvatures of the spine include lordosis, scoliosis, or kyphosis
Inspection - Gait
Evenly distributed weight. Client able to stand on heels and toes. Toes point straight ahead. Equal on both sides. Posture erect, movements coordinated and rhythmic, arms swing in opposition, stride length appropriate.
Uneven weight bearing is evident. Client cannot stand on heels or toes. Toes point in or out. Client limps, shuffles, propels forward, or has wide-based gait
Inspection - Fall Risk
Client does not fall backward.
Falling backward easily is seen with cervical spondylosis and Parkinson disease.
Temporomandibular Joint
Snapping and clicking may be felt and heard in the normal client.
Mouth opens 1–2 in. (distance between upper and lower teeth). The client’s mouth opens and closes smoothly. Jaw moves laterally 1–2 cm. Jaw protrudes and retracts easily.
Decreased ROM, swelling, tenderness, or crepitus may be seen in arthritis. Decreased muscle strength with muscle and joint disease. Decreased ROM, and a clicking, popping, or grating sound may be noted with TMJ dysfunction.
Jaw has full ROM against resistance. Contraction palpated with no pain or spasms
Lack of full contraction with cranial nerve V lesion. Pain or spasms occur with myofascial pain syndrome.
Sternoclavicular Joint
There is no visible bony overgrowth, swelling, or redness; joint is nontender
Swollen, red, or enlarged joint or tender, painful joint is seen with inflammation of the joint
Cervical, Thoracic, and Lumbar Spine
Cervical and lumbar spines are concave; thoracic spine is convex. Spine is straight (when observed from behind).
A flattened lumbar curvature may be seen with a herniated lumbar disk or ankylosing spondylitis. Lateral curvature of the thoracic spine with an increase in the convexity on the curved side is seen in scoliosis. An exaggerated lumbar curve (lordosis) is often seen in pregnancy or obesity. Unequal heights of the hips suggest unequal leg lengths
Nontender spinous processes; well developed, firm and smooth, nontender paravertebral muscles. No muscle spasm.
Compression fractures and lumbosacral muscle strain can cause pain and tenderness of the spinal processes and paravertebral muscles
Flexion of the cervical spine is 45 degrees. Extension of the cervical spine is 45 degrees
Cervical strain is the most common cause of neck pain. It is characterized by impaired ROM and neck pain from abnormalities of the soft tissue (muscles, ligaments, and nerves) due to straining or injuring the neck. . Cervical disk degenerative disease and spinal cord tumors are associated with impaired ROM and pain that radiates to the back, shoulder, or arms. Neck pain with a loss of sensation in the legs may occur with cervical spinal cord compression.
Normally the client can bend 40 degrees to the left side and 40 degrees to the right side
Limited ROM is seen with neck injuries, osteoarthritis, spondylosis, or disk degeneration
Normally the client can bend 40 degrees to the left side and 40 degrees to the right side
Limited ROM is seen with neck injuries, osteoarthritis, spondylosis, or disk degeneration
Client has full ROM against resistance. Strength 5/5
Decreased ROM against resistance is seen with joint or muscle disease
Flexion of 75–90 degrees, smooth movement, lumbar concavity flattens out, and the spinal processes are in alignment.
Lateral curvature disappears in functional scoliosis; unilateral exaggerated thoracic convexity increases in structural scoliosis. Spinal processes are out of alignment.
Lateral bending capacity of the thoracic and lumbar spines should be about 35 degrees, hyperextension about 30 degrees, and rotation about 30 degrees
Low back strain from injury to soft tissues is a common cause of impaired ROM and pain in the lumbar and thoracic regions. Other causes of impaired ROM in the lumbar and thoracic areas include osteoarthritis, ankylosing spondylitis, and congenital abnormalities that may affect the spinal vertebral spacing and mobility.
Measurements are equal or within 1 cm. If the legs still look unequal, assess the apparent leg length by measuring from a nonfixed point (the umbilicus) to a fixed point (medial malleolus) on each leg.
Unequal leg lengths are associated with scoliosis. Equal true leg lengths but unequal apparent leg lengths are seen with abnormalities in the structure or position of the hips and pelvis.
Shoulders, Arms, and Elbows
Shoulders are symmetrically round; no redness, swelling, deformity, or heat. Muscles are fully developed. Clavicles and scapulae are even and symmetric. The client reports no tenderness.
Flat, hollow, or less rounded shoulders are seen with dislocation. Muscle atrophy is seen with nerve or muscle damage or lack of use. Tenderness, swelling, and heat may be noted with shoulder strains, sprains, arthritis, bursitis, and degenerative joint disease (DJD)
Extent of forward flexion should be 180 degrees; hyperextension, 50 degrees; adduction, 50 degrees; and abduction 180 degrees.
Painful and limited abduction accompanied by muscle weakness and atrophy are seen with a rotator cuff tear. Client has sharp catches of pain when bringing hands overhead with rotator cuff tendinitis. Chronic pain and severe limitation of all shoulder motions are seen with calcified tendinitis.
Extent of external and internal rotation should be about 90 degrees, respectively. The client can flex, extend, adduct, abduct, rotate, and shrug shoulders against resistance
Inability to shrug shoulders against resistance is seen with a lesion of cranial nerve XI (spinal accessory). Decreased muscle strength is seen with muscle or joint disease.
Elbows are symmetric, without deformities, redness, or swelling.
Redness, heat, and swelling may be seen with bursitis of the olecranon process due to trauma or arthritis.
Degree of pronation, and 90 degrees of supination. Some clients may lack 5–10 degrees or have hyperextension
Decreased ROM against resistance is seen with joint or muscle disease or injury.
Wrists, Hands, and Fingers
Wrists are symmetric, without redness or swelling. They are nontender and free of nodules.
Swelling is seen with rheumatoid arthritis. Tenderness and nodules may be seen with rheumatoid arthritis. A nontender, round, enlarged, swollen, fluid filled cyst (ganglion cyst) may be noted on the wrists Signs of a wrist fracture include pain, tenderness, swelling, and inability to hold a grip; as well as pain that goes away and then returns as a deep, dull ache. Extreme tenderness occurs when pressure is applied on the side of the hand between the two tendons leading to the thumb
Client tolerates test without extreme pain.
Extreme pain may indicate rheumatoid arthritis and psoriatic arthritis of the hand
No tenderness palpated in anatomic snuffbox.
Snuffbox tenderness may indicate a scaphoid fracture, which is often the result of falling on an outstretched hand.
Normal ROMs are 90 degrees of flexion, 70 degrees of hyperextension, 55 degrees of ulnar deviation, and 20 degrees of radial deviation. Client should have full ROM against resistance.
Ulnar deviation of the wrist and fingers with limited ROM is often seen in rheumatoid arthritis. Increased pain with extension of the wrist against resistance is seen in epicondylitis of the lateral side of the elbow. Increased pain with flexion of the wrist against resistance is seen in epicondylitis of the medial side of the elbow. Decreased muscle strength is noted with muscle and joint disease
If symptoms (tingling, numbness, burning, or pain) develop within a minute with Phalen test, CTS is suspected. Client may report tingling, numbness, and pain with CTS
Tingling or shocking sensation experienced with test for Tinel sign. Median nerve entrapped in the carpal tunnel results in pain, numbness, and impaired function of the hand and fingers
If the client responds with a motion that resembles shaking a thermometer (flick signal), CTS may be suspected. However, the flick signal was originally claimed to be 93% sensitive and 95% specific for CTS, but subsequent investigations have found it performs less well
Client can raise thumb up from the plane and stretch the thumb finger pad to the little finger pad
Client cannot raise the thumb up from the plane and stretch the thumb pad to the little finger pad. This indicates thumb weakness in CTS
Hands and fingers are symmetric, nontender, and without nodules. Fingers lie in straight line. No swelling or deformities. Rounded protuberance noted next to the thumb over the thenar prominence. Smaller protuberance seen adjacent to the small finger
Pain, tenderness, swelling, shortened finger, depressed knuckle, finger crossing over adjacent finger when making a fist, or inability to move the finger may be seen with finger fractures Swollen, stiff, tender finger joints are seen in acute rheumatoid arthritis. Boutonnière deformity and swan neck deformity are seen in long-term rheumatoid arthritis. Atrophy of the thenar prominence may be evident in CTS. In osteoarthritis, hard, painless nodules may be seen over the distal interphalangeal joints (Heberden nodes) and over the proximal interphalangeal joints (Bouchard nodes)
Normal ranges are 20 degrees of abduction, full adduction of fingers (touching), 90 degrees of flexion, and 30 degrees of hyperextension. The thumb should easily move away from other fingers and 50 degrees of thumb flexion is normal. The client normally has full ROM against resistance.
Inability to extend the ring and little fingers is seen in Dupuytren contracture. Painful extension of a finger may be seen in tenosynovitis (infection of the flexor tendon sheathes; Decreased muscle strength against resistance is associated with muscle and joint disease
Hips
Buttocks are equally sized; iliac crests are symmetric in height. Hips are stable, nontender, and without crepitus
Instability, inability to stand, and/or a deformed hip area are indicative of a fractured hip. Tenderness, edema, decreased ROM, and crepitus are seen in hip inflammation and Degenerative Joint Disease. The most common injuries of the hip and groin region in athletes are in sports involving kicking or skating, especially with sudden changes in direction; the most common injury is adductor/groin tear. Strains, a stretch or tear of muscle or tendons, often occur in the lower back and the hamstring muscle.
Normal ROM: 90 degrees of hip flexion with the knee straight and 120 degrees of hip flexion with the knee bent and the other leg remaining straight. 45–50 degrees of abduction 20–30 degrees of adduction 40 degrees internal hip rotation 45 degrees external hip rotation 15 degrees hip hyperextension
Inability to abduct the hip is a common sign of hip disease. Pain and a decrease in internal hip rotation may be a sign of osteoarthritis or femoral neck stress fracture. Pain on palpation of the greater trochanter and pain as the client moves from standing to lying down may indicate bursitis of the hip
If pain client had is reproduced or worsens, the test is positive, which is seen with a herniated disc.
Knees
Knees symmetric, hollows present on both sides of the patella, no swelling or deformities. Lower leg is in alignment with the upper leg.
Knees turn in with knock knees (genu valgum) and turn out with bowed legs (genu varum). Swelling above or next to the patella may indicate fluid in the knee joint or thickening of the synovial membrane.
Nontender and cool. Muscles firm. No nodules.
Tenderness and warmth with a boggy consistency may be symptoms of synovitis. Asymmetric muscular development in the quadriceps may indicate atrophy
No bulge of fluid appears on medial side of knee.
Bulge of fluid appears on medial side of knee, with a small amount of joint effusion.
No movement of the patella is noted. Patella rests firmly over the femur
Fluid wave or click palpated, with large amounts of joint effusion. A positive ballottement test may be present with meniscal tears
Normal ranges: 120–130 degrees of flexion; 0 degrees of extension to 15 degrees of hyperextension. Client should have full ROM against resistance
Osteoarthritis is characterized by a decreased ROM with synovial thickening and crepitation. Flexion contractures of the knee are characterized by an inability to extend knee fully. Decreased muscle strength against resistance is seen in muscle and joint disease
Pain or clicking is indicative of a torn meniscus of the knee. There are a number of provocative knee tests for knee and ligament injuries, which can be seen in Budoff and Nirschl
Ankles and Feet
Toes usually point forward and lie flat; however, they may point in (pes varus) or point out (pes valgus). Toes and feet are in alignment with the lower leg. Smooth, rounded medial malleolar prominences with prominent heels and metatarsophalangeal joints. Skin is smooth and free of corns and calluses. Longitudinal arch; most of the weight bearing is on the foot midline.
A laterally deviated great toe with possible overlapping of the second toe and possible formation of an enlarged, painful, inflamed bursa (bunion) on the medial side is seen with hallux valgus. Common abnormalities include feet with no arches (pes planus or “flat feet”), feet with high arches (pes cavus); painful thickening of the skin over bony prominences and at pressure points (corns); nonpainful thickened skin that occurs at pressure points (calluses); and painful warts (verruca vulgaris) that often occur under a callus (plantar warts;
No pain, heat, swelling, or nodules are noted
Ankles are the most common sites of sprains, which occur with stretched or torn ligaments (tough bands of fibrous tissue connecting bones in a joint) Tender, painful, reddened, hot, and swollen metatarsophalangeal joint of the great toe is seen in gouty arthritis. Nodules of the posterior ankle may be palpated with rheumatoid arthritis
Pain and tenderness of the metatarsophalangeal joints are seen in inflammation of the joints, rheumatoid arthritis, and DJD. Tenderness of the calcaneus of the bottom of the foot may indicate plantar fasciitis. Plantar fasciitis is the most common cause of heel pain, which occurs when the strong supportive band of tissue in the arch of the foot becomes irritated and inflamed (Mayo Clinic, 2019b).
Client tolerates squeeze test without extreme pain
Extreme pain may indicate rheumatoid arthritis and psoriatic arthritis of the foot.
Normal ranges: 20 degrees dorsiflexion of ankle and foot 45 degrees plantarflexion of ankle foot 20 degrees of eversion 30 degrees of inversion 10 degrees of abduction 20 degrees of adduction 40 degrees of flexion 40 degrees of extension HAMMER TOE
Decreased strength against resistance is seen in muscle and joint disease. Hyperextension of the metatarsophalangeal joint and flexion of the proximal interphalangeal joint is apparent in hammer toe