How Injuries Heal

Have you ever dealt with an injury that seems to take forever to heal?

Our bodies utilize our immune system to promote healing whether a simple ankle sprain or a post-operative hip replacement.

In a healthy situation, our injuries heal in four progressive phases beginning with hemostasis which occurs immediately after a wound in the body. Hemostasis is the phase that stops the bleeding. Second, we have inflammation which occurs on average within 3 days of the injury. In this phase we have inflammatory cells that contribute to the removal of damaged cells and pathogens. Also in this phase, there is increased swelling, redness and warmth in which we can alleviate with cryotherapy at the area if appropriate. It should be noted that this phase may be prolonged depending on the type of injury, health of a person, and other mechanisms that may contribute to a chronic injury. The next phase is proliferation, which may last up to twenty days and focuses on creating new cell and tissue growth. The last phase is maturation and remodeling which may take up to twenty days to a year depending on the extent of the injury and health status of the person. In this phase, you may see a progression of load and stress while completing your exercise program in physical therapy. 

Different tissue types may also have different healing timelines. Muscle strains take up to between one week to six months to heal depending on the extent of the soft tissue damage. On average, ankle sprains of grades II to III take between ten to ninety days to heal appropriately. And peripheral nerve lacerations heal the slowest, as nerves grow on average one to three millimeters per day. 

What can be done to accelerate healing time?

There are many factors that contribute to the healing of an injury in the body. 

• Nutrition plays a big factor, a healthy diet brings proper nutrients into the body which is associated with healing at a faster rate compared to a poor diet that has inflammatory promoting factors. 
• As one ages, the healing rate declines. 
• Having a history of previous injuries in the same area may also contribute to poor healing and chronic inflammation unless properly guided through the healing repair phases. 
• Lifestyle factors can play either a negative or positive role depending on the choice such as having a smoking history or living an active lifestyle with exercise. 
• Comorbidities such as diabetes, kidney disease, heart disease, COPD can delay healing time on average of three months depending on the extent of the injury and control of the disease. 

Although our bodies have natural healing abilities it is important to keep in mind modifiable and nonmodifiable factors that can promote or delay proper healing. 

Sources:

Therapeutic Exercise Foundations and Techniques. F.A. Davis Company

Wong, Michael. Pocket Orthopaedics Evidence-Based Survival Guide. Jones and Bartlett Learning

Robertson, E. 2019, Introduction to the Diagnostic Process, lecture notes, PT566 unit 1

Kelley et al. 2009, Journal of Orthopaedic & Sports Physical Therapy, Shoulder Guidelines Adhesive Capsulitis, JOSPT