Trauma

• Physical injury or wound that is produced by an external or internal force

• Mechanical Injury - force or mechanical energy is that which changes that state of rest or uniform motion of matter

  • When a force applied to any part of the body results in a harmful disturbance in function and/or structure - a mechanical injury occurs

5 Types of Tissue Loading

• Compression - shortens and widens tissue

• Tension - pulls or stretches tissue

• Shearing - rubbing (blisters)

• Bending - tension and compression

• Torsion - twisting

Traumatic vs. Overuse Injuries

• Injuries are either caused by trauma or overuse

• All  injuries are acute, if the injury does not heal properly it becomes chronic

• Injuries that result from overuse occur with the repetitive dynamics of running, throwing, or jumping

Anatomical Characteristics of Muscles

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• Muscle → Fascicles → Muscle fibers (cells) → Myofibrils → Thick and thin filaments

• Muscle: Tissue of the body which primarily functions as a source of power

  • Responsible for moving extremities and external areas of the body are called skeletal muscle

Muscle Strains

• When a muscle is overstretched by tension or forced to contract against too much resistance, separation or tearing of the muscle fibers occurs.

• A muscle strain can be a stretch, tear or rip in the muscle or its tendon.

  • Grade 1: some muscle fibers have been stretched or torn

  • Grade 2: a number of muscle fibers have been torn

  • Grade 3: a complete rupture of the muscle has occurred

Muscle Cramps

• Extremely painful involuntary muscle contractions that occur commonly in the calf, abdomen or hamstrings

• Heat cramps is related to excessive loss of water and some extent several electrolytes or ions that are essential elements in muscle contraction

Muscle Guarding

• Muscle contracting in response to pain

• Body’s defense mechanism to act as a splint

Muscle Spasms

• A reflex reaction caused by trauma to the musculoskeletal system

• Clonic - involuntary muscle contraction characterized by alternate contraction and relaxation in rapid succession

• Tonic- muscle contraction characterized by constant contraction that lasts for a period of time

Muscle Soreness

• Pain caused by overexertion in exercise

  • Acute onset muscle soreness - fatigue, occurs immediately after exercise

  • Delayed onset muscle soreness (DOMS) - increased muscle tension, swelling, and stiffness

    • causes include small tears in the muscle tissue or disruption in connective tissue that holds muscle tendon fibers together

Anatomical Characteristics of Tendons

• Tough band of connective tissue that attaches muscle to bone

• Concentrates a pulling force in a limited area

• Because a tendon is usually double the strength of the muscle it serves, tears commonly occur at the muscle belly, musculotendinous junction or bony attachment

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Tendinitis/Tendinosis

• Tendinitis- inflammation of the tendon

  • Moves or slides on the other structures around it whenever the muscle contracts, if the movement is performed repeatedly the tendon can become irritated and inflamed

  • Crepitus - a crackling feel or sound that occurs by tendon’s tendency to stick to the surrounding structure while it slides back and forth

• Tendinosis - breakdown of a tendon without inflammation (degeneration)

• Tenosynovitis - inflammation of a tendon and its synovial sheath (thin layer of tissue)

Contusion

• Compression of soft tissue that results in bleeding into surrounding tissue

  • Ecchymosis - bluish-purple discoloration of the skin

Joints

• A point where two bones interest

• Necessary for all types of movement in the body involving bones

• The force generated by muscles is used to carry out movement through various joints

• Synovial joints

  • Articulations of two bones surrounded by a joint capsule lined with synovial membrane

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  • Bursitis: inflammation of bursae (pieces of synovial membrane that contain a small amount of fluid)  at sites of bony prominences between muscle and tendon

Dislocations and Subluxations

• Dislocation occurs when at least one bone in a joint is forced completely out of its normal alignment

• Subluxation is like a dislocation except that a bone comes partially out of its normal articulation then goes right back into place

Anatomical Characteristics of Ligaments

• Ligaments are composed of dense connective tissue arranged in parallel bundles of collagen composed of rows of fibroblasts

• Ligaments connect bone to bone

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Ligaments Sprains

• Occur when stress is applied to a joint that forces motion beyond its normal limits or planes of movement

• Grade 1 Sprain - stretch or separation

• Grade 2 Sprain - tearing and separation with instability

• Grade 3 Sprain - total tear of ligament which leads to instability of joint

Classification and Load Characteristics of Injuries