Muscle strains are a very common orthopedic injury. A muscle strain AKA a “pulled muscle” happens when a muscle is overstretched or torn. This can occur due to overuse, excessive muscular contraction, fatigue, etc. Muscles that are commonly “pulled” include hamstrings, calves, quads, and low back muscles.
Anatomy of a muscle strain
In order to understand the anatomy of a muscle strain, it is important to understand the structure of muscles. Muscles are large bundles of individual, long, thin muscle fibers - picture the end of a witches broom.
Grade 1: 0-5% of muscle is involved, muscle fibers are overstretched, not torn, focal tenderness and swelling, no loss of function
Grade 2: 5-50% of muscle fibers involved/torn, pain, swelling, bruising
Grade 3: 50-100% of muscle fibers involved, complete rupture of muscle, loss of function of muscle
So should I stretch it?
After straining a muscle, many people immediately feel the need to begin stretching that area. Incidentally, this is the wrong way to help the muscle heal initially. Stretching a strained muscle (or aggressively foam rolling it) further pulls the muscle fibers apart and makes it much harder for them to heal back together.
So if I can't stretch it, what should I do?
After a muscle strain (grades 1 and 2), the best way to facilitate healing is to P.O.L.I.C.E (protect, optimally load, ice, compression, elevation) the muscle. Protecting the muscle means avoiding further damage; no heavy lifting, stretching, running. Optimally loading tissue refers to the fact that you must put some light, mechanical stress on the muscle in order for your body to know how best to lay down scar tissue and remodel the area. Optimally load the muscle by doing gentle movements, active range of motion, and walking. Ice, compression, and elevation can all be used for the first week or more to control swelling, bruising and pain.
Healing times for strained muscles depend highly on the severity of the injury but below are some average healing times to consider:
Grade 1: 1-2 weeks
Grade 2: 3-8 weeks
Grade 3: 2-6 months
If you believe you may have strained a muscle, a PT can further evaluate you and personalize a rehabilitation program!