Repetitive Strain Injuries

Weights | Repetitive Strain Injuries

Strain-: Deformation of a material body under the action of applied forces www.Merriam-Webster.com

When you go to the gym and lift weights, you are causing strain in your body. As you curl with a heavier weight than you used last week, you overload the muscle and tendon tissue. As the muscle works harder than it is used to, it needs additional blood flow to carry oxygen and glucose to the area, and to carry away toxins like carbon dioxide and lactic acid. When the body is not able to get enough oxygen to the muscle/tendon, the cell walls are weakened and some of them break open, spilling the contents onto the cells next to them and leaving a microscopic hole where the cell used to be (microtrauma.) At this point, deformation (tears) of a material body (the muscle) have occurred under the action of applied force (lifting the weight.) You strained the muscle, but in a controlled way.

This microtrauma and the residual chemical changes in the muscle are responsible for the soreness you feel the next day, which is the rest day. (You either don't go the gym, or go but exercise different muscles.) The muscle has been broken down and an inflammatory process is occurring to repair it. But your body isn't just going to repair the damage that was done yesterday. It's going to determine that if you're going to be lifting that much weight, you're going to need more muscle cells! By the second day after the strain, the microtrauma is repaired and the muscle is built up stronger than it was before the strain. This normal strain-repair -improve process is going on in our bodies continuously, day after day.

Repetitive strain injuries, such as tendonitis, occur when the breaking-down phase outpaces the building-up phase. This can occur for a variety of reasons:


  • The original strain was not controlled, and more microtrauma occurred than could be healed overnight

  • The strain was controlled (not too much) but caused by an activity that you have to do every day (like walking,) so you are breaking down again before building up from the previous day

  • A systemic medical condition (like anemia or diabetes) interferes with the ability to repair at a normal rate

  • A localized and possibly very minor problem (like a joint problem in the neck) causes muscle guarding to protect it as it heals. While neither the strain from the repetitive activity your body is accustomed to, nor the strain from the guarding is excessive, the two added together exceed the rate of repair.



Successful treatment of RSI hinges upon shifting the break down-build up balance, either by slowing down the rate of break down, or by speeding up the repair process (or both.)

For the first few weeks, repetitive strain injuries are characterized by an ongoing subacute inflammatory process (little or no redness, warmth and swelling.) They respond predictably well to treatments that control the inflammation while therapy addresses the imbalance of breaking and down and building up. If the RSI persists, the inflammation resolves but changes in the structure of tendons occur that require a completely different treatment approach. Treatments that target collagen replacement and exercises that provide additional controlled strain to the healing tendon are effective for chronic RSI.

Of course, the best treatment for RSI is prevention. An ergonomic evaluation can identify risk factors that are known to contribute to RSI, and appropriate measures can be taken to mitigate them.

The physical therapy team at ProActive Physical Therapy & Rehabilitation is experienced in providing treatment for any type of repetitive strain injury, at any point in the rehabilitation process from prevention to return to normal activities (including work and sport.) We invite you to call or come by to discuss treatment options.