Medicine and Science in Sports and Exercise. Oct. 1986;18(5):489-500.
The pathological processes [of soft tissue injury and repair] at a cellular level are described in three phases: acute inflammatory, repair, and remodelling.
The management of acute soft tissue trauma is embodied in the acronym RICE for rest, ice, compression, and elevation during the first 48 to 72 h.
Additional benefit from anti-prostaglandin medications has not been clearly demonstrated in clinical trials, and if used, these medications should be restricted to the first 3 days.
Cryotherapy (crushed ice) for 10 to 20 min, 2 to 4 times/day for the first 2 to 3 days is helpful in promoting early return to full activity.
Early mobilization, guided by the pain response, promotes a more rapid return to full activity.
Early mobilization, guided by the pain response, promotes a more rapid return to full functional recovery.
Progressive resistance exercises (isotonic, isokinetic, and isometric) are essential to restore full muscle and joint function.
Rehabilitation is complete when the injured and adjacent tissues are restored to full pain-free functional capacity under competitive conditions in association with the necessary level of cardiovascular respiratory fitness.
THIS AUTHOR ALSO NOTES:
A common classification of soft tissue injuries is based on severity:
1) Grade 1 (first degree)
“Mild pain at the time of injury or within 24 h of injury, especially when stress is applies to the injury; local tenderness may or may not be present.”
2) Grade 2 (second degree)
“The person notices pain during activity and usually has to stop; pain and local tenderness are moderate to severe when the injury is stressed.”
3) Grade 3 (third degree)
“Complete or near complete rupture or avulsion of at least a portion of a ligament or tendon with severe pain or loss of function; a palpable defect may be present; stressing a ruptured ligament may, paradoxically, be painless due to the loss of continuity of the tissue.”
In a third degree ligament sprain, “the ligament may appear intact macroscopically yet have complete loss of load-carrying ability.”
Third degree ligament injury may require surgical management.
In inter-muscular hematoma, the blood tracks distally from the site of injury and appears as a bruise some distance from the site of injury, after some time.
Intra-muscular hematoma remains confined by epimysium and may take three times longer to heal than inter-muscular hematoma.
In ligaments, microscopic collagen fiber failure begins at 7 to 8% strain.
Ligament strain greater than 7 to 8% results in failure of the ligament to resume its original length after removal of the load (plastic deformation), and to more extensive collagen failure.
Ligaments strains as high as 20 to 40% can occur before signs of failure are apparent.
“Continuity of ligaments may be macroscopically apparent (e.g. arthroscopically) even with complete loss of the load-carrying capacity of the ligament.”
“The micropathology of acute soft tissue trauma has been investigated. Healing of ligaments and soft tissue injuries in general has been shown to occur by fibrous repair (scar tissue) and not by regeneration of the damaged tissue.”
[The Fibrosis Of Repair]
The phases of soft tissue injury repair are:
The Acute Inflammatory or Reaction Phase.
Lasts up to 72 hours.
Characterized by vasodilation, immune system activation of phagocytosis to remove debris, the release of prostaglandins and inflammation.
Prostaglandins play a prominent part in pain production and increased capillary permeability (swelling).
The wound is hypoxic, but macrophages can perform the phagocytosis duties anaerobically.
The Repair or Regeneration Phase.
48 hours to 6 weeks.
Characterized by the synthesis and deposition of collagen.
The collagen that is deposited is “not fully oriented in the direction of tensile strength.
Collagen fibers tend to contract between 3 and 14 weeks after injury, and perhaps for as long as 6 months, decreasing tissue elasticity. [This is probably why we note reduced range of motion during this phase.]
This phase is “largely one of increasing the quantity of the collagen” but this collagen is not laid down in the direction of stress.
The Remodeling Phase.
This phase may last up to “12 months or more.”
“The collagen is remodeled to increase the functional capabilities of the tendon or ligament to withstand the stresses imposed upon it.”
“It appears that the tensile strength of the collagen is quite specific to the forces imposed on it during the remodeling phase: i.e. the maximum strength will be in the direction of the forces imposed on the ligament.” [This could argue for the need for specific line-of-drive joint adjustments.] This phase is largely “an improvement of the quality” (orientation and tensile strength) of the collagen.