ASK THE EXPERT: How Does A Low Back Muscle Strain Occur & How is it Treated?
How does a low back muscle strain occur and how is it treated?
When force exceeds a muscle’s threshold for strength production, injury can occur. Regarding the lumbar spine musculature, lifting from a position of flexion and rotation is the most common mechanism of injury, often creating forces greater than eight times a person’s body weight. The pathogenesis of overloaded muscles can lead to involuntary shortening, loss of oxygen supply, loss of nutrient supply, and trigger point formations. When muscle is strained from severe trauma, overuse, or mechanical overload, there is a disruption of the muscle’s basic elements myosin and actin. In a normal muscle, these two proteins slide on each other as the muscle contracts. When injured, these proteins remain stuck on one another and often lead to trigger points or shortened muscle ﬁbers. Treatment for muscle strain begins with control of swelling, pain, and edema. The ﬁrst three days of treatment following injury should consist of ice, compression, and avoidance of activities that may create more injuries. Day three up until six weeks, should consist of gentle range of motion, soft tissue mobilization via dry needling or cross friction massage, and strengthening within the patient’s tolerance.
How long do muscle strains usually take to heal?
Grade I muscle strains mean that only 25% of the muscle ﬁbers were injured. These types of strains present with pain when stretched, but no strength loss during resisted testing. The strains heal between three days and two weeks. Grade II tears infer that 50% of the muscle ﬁbers are involved and normally take four to six weeks to fully heal. Grade II tears are diagnosed by pain upon stretch and pain and weakness against resistance. Grade III muscle tears usually require surgical intervention and may require from 12 weeks to one year of rehabilitation to fully heal. These tears are diagnosed when 75% to 100% of the muscle ﬁbers are injured, there is a complete loss of strength when manually tested, and the response to stretch or contraction is painless since the muscle’s nerve supply was also disrupted during the injury.
What are myofascial trigger points and how are they treated?
Myofascial trigger points are deﬁned as taut, hyper-irritable bands within a skeletal muscle that are painful with palpation. Myofascial trigger points often refer pain to other regions surrounding the tissue. They also may twitch or involuntarily contract when palpated. Research has identified an increased metabolic demand within tissues containing trigger points. In my opinion the most effective method of treating myofascial trigger points is through dry needling. Dry needling releases shortened muscles, produces local inflammation necessary for healing, and removes chemical elements responsible for pain production.