Mechanisms and Characteristics of Musculoskeletal and Nerve Trauma

Comprehensive vocabulary terms based on the lecture on musculoskeletal and nerve trauma mechanisms and characteristics.

Trauma

Physical injury or wound caused by internal or external forces.

Mechanical Injury

Injury resulting from force or mechanical energy that alters an object's state of rest or uniform motion.

Load

An external force applied to the body, causing internal reactions within tissues.

Stiffness

The ability of a tissue to resist a load, where higher stiffness indicates greater resistance to deformation.

Stress

The internal resistance of a tissue to an applied load, typically measured per unit area.

Strain

The internal change in tissue, such as a change in length, resulting in deformation.

Viscoelasticity

The property of body tissues to possess both viscous (energy dissipation) and elastic (energy return) characteristics.

Yield Point

The point at which a tissue's elasticity is nearly exceeded; beyond this point, permanent (plastic) changes or mechanical failure occur.

Tension

A force that pulls and stretches tissue.

Compression

A force that pushes or squeezes tissue.

Shearing

A force that moves across the parallel organization of tissue.

Bending

Occurs when two force pairs act at opposite ends ($4$-point bending) or when three forces cause bending ($3$-point bending).

Torsion

Loads caused by twisting in opposite directions from opposite ends.

Traumatic Injuries

Injuries that occur acutely due to a specific event, such as a direct blow.

Overuse Injuries

Injuries that develop over time due to repetitive dynamic use and microtraumas.

Chronic Injury

An injury that does not heal properly.

Muscle Strain

A stretch, tear, or rip to a muscle or adjacent tissue.

Grade $I$ Muscle Strain

Mild stretch or tear of muscle fibers with tenderness and pain on active range of motion ($ROM$), but full $ROM$ may be present.

Grade $II$ Muscle Strain

Moderate tear of muscle fibers where active contraction is painful, a divot may be palpable, and swelling and discoloration may occur.

Grade $III$ Muscle Strain

Complete rupture of the muscle or musculotendinous junction, causing significant impairment and severe initial pain.

Muscle Cramps

Painful, involuntary skeletal muscle contractions, often occurring in a shortened position.

Muscle Guarding

Involuntary muscle contraction following injury to splint the area and limit motion to reduce pain.

Clonic Muscle Spasm

A reflex reaction characterized by rapid, alternating involuntary contractions and relaxations.

Tonic Muscle Spasm

A reflex reaction characterized by a rigid contraction that lasts for a period.

Acute-onset Muscle Soreness

Transient pain experienced immediately after exercise, often accompanying fatigue.

Delayed-onset Muscle Soreness (DOMS)

Pain occurring $24-48$ hours after activity, potentially caused by microtrauma, which gradually subsides over $3-4$ days.

Tendon Load Capacity

Tendons can withstand high loads between $8,700-18,000$ $lbs/in^2$.

Tendinitis

Inflammation of the tendon marked by gradual onset, diffuse tenderness, swelling, pain, and crepitus.

Tendinosis

Degeneration of the tendon without significant inflammation, characterized by swelling, stiffness, and restricted motion.

Tendinopathy

A general term referring to either tendinitis or tendinosis without implying a specific pathology.

Tenosynovitis

Inflammation of the synovial sheath surrounding a tendon, often occurring in the long flexor tendons of the digits or the biceps tendon.

Latent Myofascial Trigger Point

A hypersensitive nodule that does not cause spontaneous pain but may restrict movement or cause weakness; it becomes painful upon palpation.

Active Myofascial Trigger Point

A hypersensitive nodule that causes pain at rest and with palpation, and may elicit a "jump sign" or referred pain.

Contusion

Injury from a sudden blow to the body, affecting tissues and resulting in hematoma formation (accumulation of blood and lymph).

Myositis Ossificans

The formation of calcium deposits in chronically inflamed and contused tissue.

Muscle Atrophy

Wasting away of muscle due to immobilization, inactivity, or loss of nerve function.

Contracture

Abnormal shortening of muscle with significant resistance to passive stretch, often resulting from scar tissue formation.

Ligament Sprain

A traumatic joint twist causing stretching or tearing of ligaments, graded from $I$ (mild) to $III$ (severe/complete tear).

Subluxation

A partial dislocation where articulating surfaces of a joint are incompletely separated but then realign.

Dislocation

Complete displacement of articulating surfaces of a joint where bones are forced out of alignment and require reduction.

Osteoarthritis

Degeneration of articular cartilage caused by changes in joint mechanics, commonly affecting weight-bearing joints.

Bursitis

Inflammation of a bursa (fluid-filled sac) due to acute irritation or constant external compression.

Capsulitis

Inflammation of the joint capsule, often due to repeated joint trauma.

Synovitis

Inflammation of the synovial membrane, which can become chronic and lead to thickening of the synovial lining.

Diaphysis

The hollow, cylindrical shaft of a long bone covered by compact bone and containing the medullary cavity.

Epiphysis

The ends of long bones composed of cancellous bone and covered by hyaline cartilage.

Periosteum

The dense, fibrous covering of bone containing blood vessels and osteoblasts.

Wolff's Law

The principle stating that bone adapts its structure to the stresses placed upon it.

Closed (Simple) Fracture

A fracture where there is little to no displacement of the fractured ends.

Open (Compound) Fracture

A fracture where the ends displace and break through the surrounding tissue.

Stress Fracture

Fractures resulting from repetitive overload or altered stress distribution, often diagnosed via bone scan.

Salter-Harris Classification

A system (Types $I-V$) used to describe fractures involving the physis (growth plate).

Apophyseal Injuries

Injuries to traction epiphyses (muscle origin/insertion sites), such as Severs disease and Osgood-Schlatter disease.

Osteochondrosis

Degenerative changes to the epiphyses of bone during rapid childhood growth, also known as osteochondritis dissecans.

Neuropraxia

Interruption in conduction through a nerve fiber due to compression or blunt trauma, primarily impacting motor function.

Pathomechanics

Poor mechanics resulting from the body's attempt to regain balance relative to its center of gravity due to poor posture.