Athletic Soft Tissue Injury & Muscle Pains (Infrared Goals)

This post might contain affiliate links. This is not medical advice. Read my disclosures and disclaimers.

As I set out to explain how red light therapy helps athletes heal, I realized I had forgotten the difference between a strain and a sprain. Below, I researched and explained the types of athletic injuries and causes of delayed-onset muscle soreness.

Takeaways:

Soft tissue injuries involve ligaments, tendons, muscles, and bursa:

Ligaments attach bones
Ligaments get sprained
Tendons attach muscles to bones
Tendons get inflamed and strained
Muscles power the body to move
Muscles get strained and bruised (they get “contusions”)
Bursa cushion joints
Bursa get inflamed

Delayed onset muscle soreness has at least six causes, including:

lactic acid buildup
connective tissue damage
inflammation
muscle damage
muscle spasm
enzyme efflux (flowing out)

The Soft Tissue Injuries that Bench Athletes

Sudden trauma and repeated misuse cause athletic soft tissue injuries. Sudden trauma includes body blows, twists, and falls. These cause sprains, strains, and bruises. Repeated trauma is a re-injury through use before healing. This causes tendinitis and bursitis.

Soccer player lying on green field, holding his head in his hands — Soccer players with soft tissue injuries healed faster with red light therapy

Sprained Ligaments

Ligaments are soft tissue connecting the ends of bones. Sprains are acute trauma injuries in ligaments. A sprain is the tearing of a ligament. Sprains typically occur in ankles, wrists, and knees. Sprained ligament symptoms include pain, swelling, bruising, and inflammation.

Soccer player kicking ball with referee behind him — Ligament damage heals faster with red light therapy

Strained Muscles and Tendons

Tendons attach muscles to bones. Strains are acute trauma injuries in muscles and in tendons. Strains are common in hamstrings, hands, and elbows. A strain is a muscle or tendon injury from a blow, twist, fall, or misuse. Overstretching and tearing are common causes of strains. Strain symptoms include weakness, inflammation, muscle spasms, swelling, pain, and cramping.

Man in bike shorts holding a red inflamed knee — Red light therapy helps athletes play longer before exhaustion causes injuries.

Contusions

Contusions are acute trauma muscle fiber injuries. A contusion is also called a bruise. Muscles bruise when hit with hard blows or are jammed against hard surfaces.

Tendinitis

Tendinitis is an overuse injury to the tendon or the tendon’s covering (the sheath). Small stresses cause injuries that do not heal before the small stresses aggravate the tendon again. The result is swelling and pain. Tendinitis is expected in the elbow, shoulder, knees, forearms, and ankles.

Bursitis

Bursitis is an overuse injury of the bursa sacs that cushion elbows, knees, hips, and heels. The small stresses that cause tendinitis can cause bursitis as well. Bursitis symptoms include swelling and pain.

Delayed Onset Muscle Soreness (DOMS) that Interferes with Play

Physical therapist pulling on leg of patient sitting across from him — Red light therapy shortens delayed onset muscle damage soreness

Delayed onset muscle soreness is muscle pain occurring 24 to 72 hours after exercise. Onset is correlated with new and/or intense exercise activity. DOMS is caused by any mixture of these conditions[1]:

lactic acid buildup
connective tissue damage
inflammation
muscle damage
muscle spasm
enzyme efflux (flowing out)

Lactic Acid Buildup that Causes DOMS

Lactic acid production results from energy demand with insufficient oxygen to make adenosine triphosphate (ATP). The muscles demand energy to move, but the lack of oxygen prevents production. Pyruvate converts to lactic acid in anaerobic conditions.

Women tennis player holding sore elbow — Red light therapy helps with tennis elbow soft tissue injuries

Connective Tissue Damage That Causes DOMS

DOMS can be caused by connective tissue damage. Connective tissue comprises collagen, reticular, and elastin fibers[2].

Exercise damages the fibers, causing delayed onset muscle pain. Collagen fibers are supportive and resist pulling tension. Reticular fibers support tissues with a different matrix but like collagen fibers. Elastin fibers rebound after stretching. Damage to the connective tissue breaks down the body’s ability to support muscles and organs.

Inflammation that Causes DOMS

Men running on indoor track — Athletes pre-conditioning with red light therapy have fewer injuries

Inflammation is a natural immune response that gathers white blood cells at an injury. Acute inflammation is healthy, but chronic inflammation is not. Chronic inflammation damages soft tissue, resulting in pain and decreased functionality. Chronic inflammation is associated with diabetes, obesity, depression, and cardiovascular disease[3].

Muscle Damage that Causes Doms

Exercise-induced muscle damage causes loss of function, reduced strength, and reduced range of motion. Muscle damage occurs when the muscle is pushed beyond its aerobic capacity[4]. Muscle damage triggers an influx of proteins that might be the source of muscle damage (and delayed onset muscle soreness) pain.

Muscle Spasms That Cause DOMS

High-intensity exercise and muscle overuse are two causes of muscle spasms[5]. A muscle spasm is a constricted muscle tightening into a cramp and can be very painful.

Enzyme Efflux that Causes DOMS

Man on soccer field holding shin while pressing forehead into field turf — Red light therapy reduces the pain of soft tissue injury.

The Enzyme Efflux theory of DOMS is that micro traumas in the muscle cause a calcium buildup that inhibits cellular energy production. This leads to protein breakdown and prostaglandins, histamines, and potassium accumulation. The lack of energy and buildup of unwanted material causes muscle soreness.

Conclusion

Soft tissue injuries include detached ligaments, sprained ligaments, detached tendons, inflamed and stretched tendons, strained muscles, bruised muscles, and inflamed bursa.

References

Sprains, Strains and Other Soft-Tissue Injuries, OrthoInfo.com, Retrieved Sep 13, 2022
Soft-Tissue Injuries, University of Rochester Medical Center, www.urmc.rochester.edu, Retrieved Sep 13, 2022
Sprains, Strains & Soft-Tissue Injuries, Boston Medical Center, bmc.org, Retrieved Sep 13, 2022
[1] Cheung K, Hume P, Maxwell L. Delayed onset muscle soreness: treatment strategies and performance factors. Sports Med. 2003;33(2):145-64. doi: 10.2165/00007256-200333020-00005. PMID: 12617692.
[2] Kamrani P, Marston G, Jan A. Anatomy, Connective Tissue. [Updated 2022 Jan 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK538534/
[3] Pahwa R, Goyal A, Jialal I. Chronic Inflammation. [Updated 2022 Jun 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK493173/
[4] Exercise Induced Muscle Damage, Physio-Pedia, Pulled Sep 14, 2022
[5] Muscle Spasms, Cleveland Clinic, Pulled Sep 14, 2022

References

https://pubmed.ncbi.nlm.nih.gov/27050245/
https://pubmed.ncbi.nlm.nih.gov/27655326/
https://pubmed.ncbi.nlm.nih.gov/16538423/
https://pubmed.ncbi.nlm.nih.gov/24249354/
https://pubmed.ncbi.nlm.nih.gov/27141153/

Athletic Soft Tissue Injury & Muscle Pains (Infrared Goals)