PHTY208 Lecture Notes - Lecture 6: Enzyme, Delayed Onset Muscle Soreness, Spasm
Pathology of soft-tissue: muscle, ligament and tendon
• Muscle injuries
o One of the most common injuries in sport
o 10% - 55% incidence
o Types of acute injuries
• Contusion
▪ Usually occurs when a muscle is subject to a sudden, heavy compressive
force, e.g. direct blow to the muscle
▪ Overlying skin remains intact
▪ Common in quadriceps: "corked thigh"
▪ Going to produce a hematoma
• Large area of local haemorrhage (bleeding)
• Pain results from accumulating blood exerting pressure on nerve
endings
• Pain increases with movement or with pressure to area
• Complication: myositis ossifications
• Occurs when haematoma calcifies
• Osteoblasts replace some of the fibroblasts in healing
process
• Observed on plain x-ray 3 wks post injury
• Increased risk
• With increasing severity
• Following a rebleed
• Inappropriate treatment e.g. heat, massage
• In case of thigh:
• Knee effusion present
• Prone knee flexion <45
• Signs
• Increase in morning pain and pain with activity
• Night pain
• Palpable lump
• Improvements cease with subsequent deterioration
• Strain/tear
▪ When some or all of the fibres fail to cope with the demands placed
upon them e.g. excessive tensile force
▪ Common in superficial, 2-joint muscles e.g. RF, hamstrings,
gastrocnemius
▪ Often occurs in deceleration - eccentric control/contraction of muscle
• A lot more load on muscle
▪ Often result in a haematoma
▪ Clinical classification
• Nature of haematoma
• Intramuscular hematoma
• Extravasation of blood within intact muscle fascia
results in increased intramuscular pressure,
subsequently compresses and limits size of
haematoma
• Intermuscular haematoma
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• Develops if fascia surrounding
muscle is torn, and extravasated
blood has access to spread into
interstitial and interfascial spaces
• Muscle severity
• Mild (1st degree)
• Minor swelling
• Minor discomfort
• No or minimal loss of strength
• No or minimal restriction of
movement
• Represents tear of few fibres
• Moderate (2nd degree)
• Significant swelling
• Significant discomfort
• Pain on contraction
• Loss of strength
• Restriction to movement
• Represents tear of significant
number of muscle fibres (half of
muscle belly)
• Severe (3rd degree)
• Complete tear of muscle
• Virtually complete loss of muscle
function
• Diagnosis of muscle injuries
• Careful patient history, clinical
examination, imaging to assist
▪ Pathobiology of muscle injury
• Skeletal muscle healing is a repair process (in contrast to bone
which regenerates)
• Heals with a scar which replaces the original tissue
• 3 phases of repair (irrespective of underlying cause i.e. contusion,
strain, etc.)
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Document Summary
In case of thigh: knee effusion present, prone knee flexion <45. Increase in morning pain and pain with activity: night pain, palpable lump. Intramuscular hematoma: extravasation of blood within intact muscle fascia results in increased intramuscular pressure, subsequently compresses and limits size of haematoma. Significant discomfort: pain on contraction, restriction to movement, represents tear of significant. Loss of strength number of muscle fibres (half of muscle belly) Severe (3rd degree: complete tear of muscle, virtually complete loss of muscle function, diagnosis of muscle injuries, careful patient history, clinical examination, imaging to assist, pathobiology of muscle injury. Skeletal muscle healing is a repair process (in contrast to bone which regenerates: heals with a scar which replaces the original tissue, 3 phases of repair (irrespective of underlying cause i. e. contusion, strain, etc. , healing of skeletal muscle. Initial trauma: ruptured myofibres contract, haematoma fills gap between myofibre stumps, chronic/overuse injuries. Focal thickening/fibrosis: repetitive microtrauma caused by overuse damages muscle fibres.
