Muscle strain is a pretty common injury that happens to a variety of athletes, from high school football and basketball players to recreational runners. Everyone can pull a muscle at some point and no one is immune. “Strain” is the general medical term for the condition, even though it’s more commonly known among the public as a pulled muscle.
“Muscle Strain” represents a “catch-all” term which covers everything from a slight twinge to a complete muscle rupture. Your body is comprised of 3 different muscle types: cardiac(heart), visceral(smooth) and skeletal muscles. Out of these three, skeletal muscles are the only muscles which we can consciously control, and unfortunately the ones we can injure. Skeletal muscles contain thousands, sometimes millions of muscle fibers which are bundled together and contained in a layer of connective tissues.
Simply put, a muscle that was strained actually had a number of muscle fibers that comprise it torn. These tears can occur if an external force pulls them apart too hard or too fast. The condition we normally call a “tear”, a “pull” or a “strain” is actually the same: a rip in some area of the muscle. The main difference is the severity. Some are definitely worse compared to others.
A mild strain, which many people simply call a “pulled muscle”, is when you create tears in around 5% of the muscle fibers in a specific muscle. The main symptom of this micro-tear is an uncomfortable twinge which might cause you to leave the court for a couple of weeks. A moderate strain is caused by a higher percentage of damaged fibers and might force you to stop training for at least a month, maybe more. A complete rupture means the muscle is severed entirely and will usually require surgery to be re-attached.
So, how do these strains actually happen?
And how come some of them cause more damaged muscle fibers than others? It is believed that there are three major causes to these ruptures. Muscles that are positioned across two joints, such as the hamstring which extends across the knee and the hip, are at the highest risk of injury. This is because covering two joints that move and stretch the muscle at the same time adds additional tension, which can often lead to tears.
Muscles are also at a higher risk of injury whilst contracting. When contracting, the muscles are getting shorter and longer simultaneously. When doing a barbell curl, for example, getting the load up towards the shoulders, compresses the biceps, and getting it back down stretches it to its starting position. The muscle can produce and sustain more tension during the lengthening (eccentric) phase of the exercise, which increases the chances of a strain occurring.
Finally, the muscle that is comprised of a higher percentage of fast-twitch to slow-twitch fibers tends to strain more easily. Fast-twitch muscle fibers contract fast and produce greater power. Because of this, they’re the ones which the body recruits for explosive activities like sprinting. It’s pretty rare occurrence for slow-twitch muscle fibers to get strained. That’s because they are used to being constantly active.
It is technically possible to sustain a rupture in almost any of the skeletal muscles in the body. For some people, it is not physiologically impossible, only very unlikely to happen. You probably won’t strain muscles deep within the body that have very specific roles. The tiny muscles in your finger, won’t cause too much of a trouble since they perform just one easy task and you won’t have to use them for heavy weight training.
The range of motion and low level of flexibility pose two major factors that contribute to the increased risk of muscle strain. In spite of the popular notion that bigger muscles are also tighter, studies have confirmed that increased lean muscle mass is, in fact, associated with greater give. It’s also been confirmed that lifting weights with a good range of motion increases your flexibility.
Even though it doesn’t seem like it when you struggle to touch your toes, the truth is that most people can force their bodies to be more flexible as time goes by. So, in order to preserve your muscle fibers, start lifting weights and don’t skip stretching, no matter how boring it is.