Muscle Contusions - Comprehensive Notes

Definition: Muscle contusion injuries occur when the muscle is subjected to a sudden forceful blunt blow.
- Source: Tero et al. 2005.
Common presentation: direct impact to a muscle with localized pain at the contact area; pain may be deep or superficial.
Pain quality and intensity: pain is often described as aching or throbbing with a typical intensity around $2/10-6/10$ (C/V).
History and context: may occur with a corky sensation; immediate pain that may or may not lead to cessation of activity depending on severity; pain typically peaks at $24-72\text{ hrs}$ post-injury; bruising is common due to high vascularity of muscle.
- Source: Brukner & Khan 2017.

Etiology: resulting from a sudden direct blow to muscle tissue leading to contusion.
Typical location: localized to the area of contact; can be superficial or deep within the muscle.
Initial clinical note: contusions may present with bruising depending on hematoma size and location.

Sudden onset of pain following a direct blow to the muscle (described as a corky sensation).
Activity modification depends on severity; may or may not stop activity.
Pain characteristics: usually immediate and peaks within the first 24-72 hours.
Bruising: common due to vascular damage; muscle tissue is highly vascularised.
- Source: Brukner & Khan 2017.

Mechanical impact causes fibre damage and rupture of microvessels within the muscle.
Consequence: leakage of fluid and blood into the interstitial space leading to haematoma formation.
Intra-muscular haematomas:
- Tend to be more self-limiting but often more painful.
- May present with less visible bruising because the hematoma is contained within the muscle.
- Source: Brukner & Khan 2017.

Aggravating factors: movements that stretch or contract the involved muscle.
Easing factors: avoidance of stretching or contracting the muscle during the acute phase.
24-hour pattern: morning stiffness is common (inflammatory component); symptoms may be activity-dependent with throbbing after activity; pain on movement when in bed in the evening.
Note: This pattern reflects the inflammatory and mechanical components of the injury.
- Source: Brukner & Khan 2017.

Observation: +/- antalgic gait if lower limb involved; protective posture or behaviour.
Visible signs: bruising, swelling, or ecchymosis depending on hematoma size.
Functional assessment: observe the patient while performing aggravating/easing tasks when tolerable (may not be feasible in irritable or very fresh injuries).
- Contusions.

AROM (Active Range of Motion): pain expected when damaged fibres are told to contract (muscle contraction).
PROM (Passive Range of Motion): pain expected in the direction opposite to AROM (when damaged fibres are being stretched).
Palpation: tenderness around the traumatized area.
Contusions.

MLT (manual muscle testing): likely painful as damaged fibres are stretched (similar to PROM).
MMT: likely weak because damaged fibres cannot generate full force.
RSC (resisted static contraction): likely painful due to contraction of damaged fibres (similar to AROM).
Contusions.

Accessory joint movements: not typically affected (no joint damage).
Neurodynamic testing: generally negative; may be positive in old injuries where there has been a deep hematoma.
Neurological signs: typically negative unless compartment syndrome is developing, which could cause nerve compression.
- Contusions.

Primary goals: control bleeding to reduce secondary injury such as hypoxia.
Protect the injured site from further trauma.
Treatment strategies: compression and ice, rest from sports, gentle mobilisation and movement within pain limits, and gentle massage of the affected muscle peripheral to the lesion.
Source: Brukner and Khan 2017.

Advise against:
- Alcohol consumption.
- Heat application in the acute phase.
- Vigorous massage.
- Vigorous stretching.
Rationale: these measures may worsen bleeding, inflammation, or pain.
Source: Brukner & Khan 2017.

Goals: restore muscle function through a progressive program of stretching and strengthening.
Approach: move from protection to gradually increasing load in a controlled manner.
Source: Brukner & Khan 2017.

Early phase: rest and protection with gentle, pain-limited activities; gradual introduction of mobility and light massage around the lesion.
Intermediate phase: progressive stretching and gentle strengthening as pain allows.
Late phase: functional training and sport-specific drills as tolerated.
The progression should be guided by pain, swelling, and functional tolerance.
Source: Brukner & Khan 2017.

Intra-muscular hematomas, though potentially less visible, can be very painful and may delay return to activity.
The presence of bruising does not always correlate with symptom severity; hematoma location (intra-muscular vs subcutaneous) affects both bruising visibility and pain.
Neurodynamic tests can be negative in acute contusions but may become positive in old injuries with hematoma sequelae.
Monitor for signs of compartment syndrome (neurological symptoms, severe pain disproportionate to exam), which would warrant urgent assessment.

Inflammatory response to tissue injury: haematoma formation triggers local inflammation.
Tissue healing follows a sequence: injury → inflammation → repair → remodelling; movement and loading should be gradually reintroduced to promote proper fibre alignment and strength.
Pain with contraction (AROM) and pain with stretch (PROM/MLT) reflect muscle fibre damage and mechanical disruption.

Ethical: ensure accurate diagnosis to avoid unnecessary restrictions or premature return to sport that could worsen injury.
Practical: balance between immobilization for protection and early mobilization for preventing stiffness and promoting healing.

Pain scale range observed: $2/10-6/10$ .
Acute phase time course for peak symptoms: $24-72\text{ hrs}$ after injury.
Key literature: Brukner & Khan 2017; Brukner & Khan referenced throughout; additional sources include Garrett (1996); Järvinen & Lehto (1993); Tero et al. (2005)].

Garrett, W. (1996). Muscle strain injuries. American Journal of Sports Medicine, 24(6 Suppl), S2-8.
Järvinen M, Lehto MUK. The effect of early mobilization and immobilization on the healing process following muscle injuries. Sports Med. 1993;15:78-89.
Tero A, Järvinen H, Teppo LN, Järvinen M, Hannu K & Järvinen M. Muscle Injuries. Am J Sports Med. 2005; 33: 745-764.
Brukner, P. & Khan, K. (2017). Brukner & Khan's Clinical Sports Medicine (4th ed.)."