Inflammation and Repair in Soft Tissue in Sports Injuries
Frequently clients have stated that they don’t understand the reason behind swelling & bruising when they sustain an injury. It is important to understand the processes of injury healing as much as possible
Healing is the way the body replaces damaged tissue with living tissue at the site of injury. Every connective tissue in the body must go through the same processes once it has sustained some damage regardless of severity.
It is widely known that there are 4 distinct but overlapping phases, Bleeding, Inflammation, Proliferation & Remodelling
There must be specific rehabilitation and treatment based on the principles of tissue healing
The bleeding phase occurs immediately following injury and is short lived lasting from about on average 4-6 hours.
Once an injury has been sustained, the damaged blood cells bleed, the site of the injured tissue will consist of dead cells and extravasated blood.
The second inflammatory phase is an essential part of tissue repair. It has a rapid onset post injury, within a few hours, and increases in strength to reach its maximum between 1- and 3-days post injury. A natural inflammatory reaction occurs involving a blood vessel and cellular response with exuded fluid resulting in bruising and cellular activity. The inflammation is triggered by blood vessels enlarging and becoming more permeable (the ability to allow liquids to pass through it), this is initiated by chemical responses.
Typically, acute inflammation presents itself as swelling, bruising, increased temperature, pain and loss in function at the injury site.
Proliferation Phase – Sub Acute
Repair material is generated at this stage where scar tissue is produced. This starts from 2-3 days after the initial incident and reaches its peak at 2-3 weeks. The injured tissue causes the release of chemicals which affect local blood vessels and allows leakage of blood into the area which form the exudate or swelling in the area. This exudate dilutes any of the
irritant substances in the damaged area and due to high fibrinogen content, a soluble protein present in blood plasma, which produces fibrin, which starts to build a fibrin clot which bridges the gap in the damaged tissue.
The formation of collagen (the main structural protein of connective tissue) and new local blood vessels occur to aid blood flow to damaged blood vessels from the incident.
Fibrin forms strands that grow into the network somewhat like a fish net. The fibrin net captures circulating platelets and forms a plug that seals the damaged vessel, sometimes completely plugging it so circulation through the damaged vessel stops. The area is left with a mass of whole blood and cellular debris which together are known as a hematoma. As the hematoma is formed pressure is exerted on undamaged pain nerves in the area resulting in additional pain. The body responds with muscle spasm and a reduction of muscular strength and range of motion. These responses are efforts by the body to protect itself by splinting the area and thus preventing aggravation of the injury.
Pain is a good indicator of how much movement / exercise an injured area will tolerate and should be within the tissues limits. If this is monitored well the process of healing can be accelerated.
Around 2-3 weeks post injury (depending on the severity) collagen fibres mature and the remodelling of the tissue occurs. As the collagen matures it aligns with the typical stresses the injury site must endure. There are different types of collagen, but one in particular is removed from the injury site and replaced with a type which has a greater tensile strength. This type of remodelling can happen for months and even years after the initial incident.
As previously stated, it is essential that in every stage of healing the treatment and rehab is specific and safe. As the injury progresses through the stages of healing, the treatment & rehabilitation must progress accordingly. If you want to return to participate in sport, it is essential that you progress through the stages of healing & rehab and adhere to sports specific exercises & rehab to prevent recurrence of the injury.
The onset and resolution are swifter in more vascular tissues, for example muscles than poorly vascularised tissues eg tendons. As well as trauma or sporting injuries causing inflammation mechanical irritation, repeated minor trauma, excessive heating and cooling can lead to an inflammatory event.