Injury and Healing Within Sports Physiotherapy
Top Contributors - Wanda van Niekerk, Robin Tacchetti, Jess Bell, Ewa Jaraczewska, Tarina van der Stockt and Kim Jackson
Introduction[edit | edit source]
Soft tissues provide support and have a protective function in the body. These tissues are made of cells, fibres and non-cellular matrix material with collagen being the most abundant component. When a soft tissue injury occurs, the cardinal signs of inflammation appear: redness, swelling, pain, loss of motion and heat. Healing is a process which includes the following stages: inflammation, repair and remodelling. Each phase of healing overlaps and has no definitive time frame.
Connective Tissue[edit | edit source]
It is important that physiotherapists involved in the prevention and management of sports injuries understand the biological and mechanical nature of tendons, ligaments and capsules (collectively these are known as connective tissue). Two important functions of connective tissue are to:
Three elements are found in all connective tissues, namely cells, fibres and extra-cellular matrix. Collagen is the most abundant fibre in connective tissues and is composed of smaller units called tropocollagen. There are many types of collagen and each has different properties. Tendons are mainly made up of type I collagen. Collagen resists elongation and stress whereas the extracellular matrix resists compression.
The different types of tissue in the body are all derived from one basic cell. They differentiate into specialised cells based on the stimulus that is provided. The mechanical behaviour of these different types of tissues is influenced by:
- The physical properties of collagen and other fibres
- Arrangement of fibres
- Size of collagen fibres
- Proportion of collagen fibres and other fibres
- Maturity of collagen fibres
- Composition and hydration status of ground substance
Stages of Healing[edit | edit source]
Inflammatory Phase[edit | edit source]
The first stage of healing is inflammation. This phase, which generally peaks between day 1 and 3 is marked by redness, swelling, pain, heat and disruption of function of the affected tissue. The purpose of the inflammatory phase is to:
- Control the effects of the injury
- Return the injured tissue to its normal state
The aim during this period is to prevent excessive inflammation and move through the next stages of healing to full recovery.
Physiologically the inflammatory process consists of the following events:
- Histamine is released from damaged capillaries causing increased permeability and vessel dilation
- Prostaglandins maintain vasodilation
- Amines cause contraction of smooth muscle
- Phagocytes clear debris
- Mediators are released to stimulate the proliferative phase
Inflammation can be seen as unwelcome, but it is the first step to healing. The inflammatory phase prepares the tissue for the repair process. This chemically controlled cascade is crucial for healing and optimal soft tissue regeneration is supported by this process. The use of NSAIDs during this crucial phase may negatively affect long-term tissue healing.
There are treatments designed to limit the above chemical process when it becomes excessive. There are two drug classes used to inhibit the inflammatory process: non-steroidal anti-inflammatories (NSAIDs); and corticosteroids. NSAIDs not only have anti-inflammatory properties, but are pain-relieving as well. Corticosteroids are usually injected to the site of pathology and can reduce inflammation and pain. However, they can cause inhibition of collagen synthesis, which affects healing. 
Chronic Inflammation[edit | edit source]
Inflammation that continues on for several months to several years is referred to as chronic inflammation. This phenomenon occurs when macrophages have been unable to clear the wounded area of foreign substances. This area becomes surrounded with collagen/scar to isolate it from the body called a granuloma. 
Proliferation Phase[edit | edit source]
Once the inflammatory process is complete, tissue repair can occur. This phase consists of two actions, fibroplasia (fibrous material production) and angiogenesis (new blood vessel formation).
Physiologically during this phase, the following occurs:
- Capillary buds form and grow towards the injured area
- Granulation tissue is created by capillary loops initiating blood flow
- Phagocytosis by specialised white blood cells
- Lymphatic vessels create a new drainage system
- Fibroblasts contract the wound, pulling the edges towards each other
Remodelling[edit | edit source]
The remodelling stage may last anywhere from 3 weeks to 12 months and overlaps the repair stage. The aim of remodelling is to decrease wound size, increase the scar strength and alter the direction of collagen fibres. Refining and altering collagen during this time facilitates increased fibre strength. Physiologically the following occurs during this phase:
- Contraction of granulation tissue
- Fibroblasts form intercellular bonds
- Cross-bonds between cells form, increasing collagen strength
- Continuous turnover of collagen
- Type three collagen is replaced by type one collagen
The final collagen fibre tissue arrangement should match the function of the tissue. The alignment is dependent on the stresses imposed on the tissue during healing.
Healing[edit | edit source]
Healing begins immediately, but collagen is generally not laid down until the 5th day post-injury. This period of time is referred to as the “lag phase”. During the lag time, physiotherapy goals are directed toward oedema control and resolving pain. The graph on the right shows how the different phases of healing are not discrete and that they overlap.
Tissue mobilisation focused on realigning collagen fibres can begin once collagen synthesis has been initiated. Mild stress during this stage of rehabilitation is referred to as mechanical loading and is necessary to stimulate collagen fibre alignment.
Mechanical Loading[edit | edit source]
Physiotherapists can play a key role in optimally influencing the healing process. The overall therapeutic aim of any stimulus is to affect two major processes:
- Repair of the injured tissue
- Adaptation of the tissue to load (or training stimulus in athletes)
Macro trauma (like an impact or collision injury in sports) or microtrauma (like an overuse injury) will elicit a tissue response. A corrective or adaptive load is necessary for the resolution of an injury.
The goal of mechanical loading is to improve injured tissue tensile strength through compression, tension or shear force. A load can be very light like a tickle, to a very high load like a manipulation. If the load applied is too little or too much, it can result in a substandard repair and potentially lead to a chronic condition. As the tissue strengthens, the applied load can be enhanced by ensuring that the tissue is not overloaded. Too much tension can cause the collagen fibres to misalign in the developing adhesions, leading to a regression of the inflammatory process.  The video below provides a simple explanation of the relationship between load and tissue capacity and how this links to injury.
Read more on how mechanical load stimulates adaptation in this article (see Figure 1 in the article):
Effects of Mechanical Loading[edit | edit source]
- After an injury a short period of protection / rest is initially required
- Longer periods of protection / rest are deleterious and result in adverse changes in tissue biomechanics and morphology within 2-3 weeks
- Progressive mechanical loading is more likely to restore strength and morphological characteristics
Appropriate Time for Mechanical Loading[edit | edit source]
The two figures below provide some insight on the appropriate time to add load after an injury. Figure 1 shows that the collagen content is approximately equal to the tensile strength of the tissue. As the collagen changes from immature type III to type I over time, the tensile strength of the tissue increases. Figure 2 displays the stages of healing in relation to tensile strength. For optimal healing, the applied load must remain within the tensile capabilities of the tissue.
Loading by Physiotherapists[edit | edit source]
Physiotherapists can apply mechanical loads to injured tissues with different techniques such as massage, manual therapy, electrotherapy, such as ultrasound, and exercise.  These interventions promote repair and remodelling of injured tissues. An indicator that the tissue is being stimulated and remodelled is when the patient feels mild discomfort. Examples of mechanical loading are deep transverse friction massage which may improve adhesions and increase the tensile strength of the healing scar. However. there is limited evidence to support this technique. Please see the below video for an example of deep transverse friction massage by Ben Benjamin. Another example of mechanical loading is specific soft tissue mobilisation (SSTM) as explained by Hunter. The video below provides some more insight into SSTM.
In the video below, Professor P. Glasgow provides a clinical perspective on maximising healing of muscle injury using mechanical loading.
Calculating the Correct Load[edit | edit source]
Physiotherapists are skilled in determining the correct amount and type of load to apply to a specific tissue. There are different models of loading available in the literature. Read more about these here:
- Tissue Homeostasis Model: The pathophysiology of patellofemoral pain: a tissue homeostasis perspective.
- Optimal Load Model: Optimal loading: key variables and mechanisms.
Loading Feedback[edit | edit source]
Patient feedback is critical during each stage of loading to ensure collagen alignment and proper healing. Patient reported outcomes can be valuable. Asking the patient to monitor for swelling, stiffness and pain for 24 hours can help the therapist gauge the correct loading intensity. In addition, therapists can monitor swelling using girth measurements. See below for an example of a girth measurement of the ankle by CRT Technologies:
Soft Tissue Injury Management[edit | edit source]
Traditional Acute Injury Management[edit | edit source]
Traditional treatment for soft tissue injury has been referred to as RICE (rest, ice, compression and elevation). Unfortunately, rest or immobilisation of soft tissue injury can result in joint stiffness, weak ligaments and delayed healing. Total immobilisation should be dedicated to bone injury or a complete rupture where movement could cause further damage. Conversely, exercise and pain-free movement within a protected support can strengthen ligaments and increase collagen turnover. 
New Thoughts on Acute Injury Management[edit | edit source]
Goals of acute phase management:
- Protect the injured tissue from further injury
- Control pain
- Limit swelling
- Promote optimal healing
Considering the goals of treatment during the acute phase of an injury, Bleakley et al updated the PRICE regime to POLICE which represents Protection, Optimal Loading, Ice, Compression and Elevation.
|PEACE (day 1 -3)||and||LOVE (after a few days)|
|P: protect the area||L: optimal loading to repair and remodel tissue|
|E: elevate||O: optimistic expectations by the patient coincide with better outcome|
|A: avoid anti-inflammatories medication to allow for natural inflammatory process to occur||V: vascularisation - pain-free aerobic exercise to increase blood flow|
|C: compression||E: exercise - pain-free exercise|
|E: educate the patient on an active approach to therapy versus a passive one|
Healing Times[edit | edit source]
With proper management, various tissues will take different amounts of time to heal fully. Understanding the specific tissue helps target the appropriate timing for incremental loading during the remodelling stage. Ian Horsley estimates the time expected to fully heal by tissue below:
Soft tissues need to go through the three stages of inflammation, repair and remodelling to fully heal. Physiotherapists can assist with healing by understanding the timeline of the involved tissue, and by knowing when and how much load to apply during the remodelling phase. Good clinical decisions will be necessary to fine-tune interventions and to monitor symptoms. All of these factors will provide for optimal soft tissue recovery.
Resources[edit | edit source]
- Inflammation Acute and Chronic
- Wound Healing
- Figure Eight Measurement of the Hand
- Figure of Eight Method of Measuring Ankle Joint Swelling
- Peace and Love Principle
Reference[edit | edit source]
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