Chapter 9: Mechanisms and Characteristics of Sports Trauma
Mechanical Injury
Tissue Properties
Tissue Stresses
Soft Tissue Trauma
Skin Injuries
Three types of muscle
Cardiac
Smooth
Striated
Acute Muscle Injuries
Contusions
Hematoma results from blood and lymph flow into surrounding tissue
Muscle Strain Grades
Grade I –
Grade
II –
Grade
III-
Pathologically,
strain is very similar to contusion or sprain with capillary or blood vessel
hemorrhage
Tendon Injuries
Muscle Cramps and Spasms
Overexertional Muscle Problems
Two types of soreness
Acute-onset muscle soreness - accompanies fatigue, and is transient muscle pain experienced
immediately after exercise
Delayed-onset muscle soreness (DOMS) - pain that occurs 24-48 hours following activity that
gradually subsides (pain free 3-4 days later)
Muscle Stiffness
Muscle Cramps
Muscle Guarding
Myofascial Trigger Points
Chronic Musculoskeletal Injuries
Myositis/fascitis
Calcium at the heel
Atrophy and Contracture
Generally the result of a muscle injury which impacts the joint, resulting in accumulation of scar
tissue
Synovial Joints
Joint Capsule
Bones are held together by a fibrous cuff
Consists of bundles of collagen and function to maintain relative joint position
Extremely strong and can withstand cross sectional forces
Will be slack or taut depending on joint movement
Ligaments
Synovial Membrane
Articular Cartilage
Provides firm flexible support - semifirm connective tissue with primarily ground substance
No direct blood or nerve supply
Fibrocartilage: makes up vertebral disks, symphysis pubis and menisci
Nerve Supply
Capsule, ligaments, outer aspects of synovial membrane and fat pads are well supplied
Inner structures (synovial membrane, cartilage and articular cartilage) also supplied
Myelinated mechanoreceptors provide joint position sense in fibrous capsule
Non-myelinated fibers supply blood vessels and pain receptors
Types of Synovial Joints
6 types
ball and socket –
hinge pivot ellipsoidal saddle gliding Functional Synovial Joints
Synovial Joint Stabilization
Articular Capsule and Ligaments
Synovial Joint Trauma
Synovial Joint Injury Classifications
Graded based on the severity of injury
Grade I - some pain, minimal loss of function, no abnormal motion, and mild point tenderness
Grade II - pain, moderate loss of function, swelling, and instability
Grade III - extremely painful, inevitable loss of function, severe instability and swelling, and
may also represent subluxation
Can result in joint effusion and swelling, local temperature increase, pain and point tenderness,
ecchymosis (change in skin color) and possibly an avulsion fracture
Most vulnerable joints include ankles, knees, and shoulders
Sometimes difficult to distinguish between sprain and tendon strain
Repeated joint twisting could result in arthritis or chronic inflammation
Acute Synovitis
Subluxations, Dislocations and Diastasis
High level of incidence in fingers and shoulder
Subluxations are partial dislocations causing incomplete separation of two bones
Luxation presents with total disunion of bone apposition between articular surfaces
Diastisis is the disjointing of 2 parallel bones or rupture of a solid joint (symphysis pubis)
Ankle Edema
Chronic Joint Injuries
Osteochondrosis
Bursitis
Bone Functions
Body support
Organ protection
Movement (through joints and levers)
Calcium storage
Formation of blood cells (hematopoiesis)
Types of Bone
Classified according to shape
Flat bones - skull, ribs, scapulae
Irregular bones - vertebrae and skull
Short bones- wrist and ankle
Long bones - humerus, ulna, tibia, radius, fibula, femur
bones most commonly injured
Bone Trauma Classifications
Periostitis Acute bone fractures Type of fractures include, depressed, greenstick, impacted, longitudinal, oblique, serrated, spiral,
transverse, comminuted, blowout, and avulsion
Stress fractures- no specific cause but with a number of possible causes
Overload due to muscle contraction, altered stress distribution due to muscle fatigue, changes in
surface, rhythmic repetitive stress vibrations
Major signs and symptoms include focal tenderness and pain, (early stages) pain with activity,
(later stages) pain becomes constant and more intense, particularly at night, positive percussion
tap test
Common sites involve tibia, fibula, metatarsal shaft, calcaneus, femur, pars interarticularis, ribs,
and humerus
Management varies
More easily managed and healed if on compression side of bone vs. tension (may result in
complete fx)
Running Fracture
Nerve Trauma
Nerve Injuries
Two main causes of injury - compression and tension
May be acute or chronic
Body Mechanics
Microtrauma and Overuse Syndrome
Injuries as a result of abnormal and repetitive stress and microtraumas fall into a class with
certain identifiable syndromes
Frequently result in limitation or curtailment of sports involvement
Often seen in running, jumping, and throwing activities
Some of these injuries while small can be debilitating
Repetitive overuse and stress injuries include
Achilles tendinitis, shin splints, stress fx, Osgood-Schlaters disease, runners and jumpers knee,
patellar chondromalacia and apophyseal avulsion
Postural Deviations
Often an underlying cause of injury
May cause unilateral muscle use as well as bony and soft tissue asymmetries
Results in poor pathomechanics
Imbalance is manifested by postural deviations as body tries to regain balance relative to CoG
Injury generally becomes chronic and participation must stop
Athletic trainer should attempt to correct postural conditions
Postural conditions can make athletes exceedingly more prone to injury