Leverage. It's a word we hear often enough, but what does it mean to you? We often think of leverage as having the upper hand in a situation, an advantage. Today, let’s see how our bodies use leverage to allow us smooth, strong movement as we do our stuff.
First, let’s make sure we are all on the same page with what leverage is. Tortora and Grabowski, 2003, describe leverage as an advantage when a smaller effort can move a heavier load. A lever can be a bone. Effort would be your muscle contraction, and the fulcrum would be the joint that hinges bringing the bones closer together. A load, or resistance, opposes the movement. Movement occurs at the joint, or fulcrum, when the effort is greater than the load.
There are three different types of levers and they categorized by the positions of the fulcrum (F), the effort (E) and the load (L). We'll call them first-class levers, second-class levers, and you guessed it, third-class levers.
Here is our first scenario: You are sitting at your desk, muddling through your taxes or the Obamacare website, and you notice a pain in your neck as you nod off, again. In this case, the weight of your head is the load (L), is in front of the fulcrum (F) which is your atlanto-occipital joint. The effort (E) comes from the muscles that attach the back of your head to your spine. They are working very hard to keep your head up. No wonder we all get massage and stretch to relieve the tension in our necks! This EFL arrangement is a great example of a first-class lever. As an aside, a pair of scissors works the same way. Your thumb and fingers contribute the Effort, the Fulcrum is the hinge and the Load is the paper. EFL.
Our second-class lever is the strongest. With our days getting longer and hopefully warmer, I've been thinking about the garden which makes me think of moving heavy loads in the wheelbarrow. In this example, the Fulcrum is the wheel, Load is all the dirt or weeds we have to move and Effort is applied to the handles. Because the load is close to the fulcrum, we use less effort to lift such a heavy load. It is the strongest because E is further from the pivot. FLE. Most anatomists believe that we don't have any second-class levers in the body. Some people contend that the action of the calves attaching to and lifting the heel produces a similar wheelbarrow effect.
The third-class and most common kind of lever is when the effort is situated between the fulcrum and the load. FEL. Here's the vignette: Imagine you're at the gym doing bicep curls. The weight is in your hand (load), and your biceps brachii muscle (effort) contracts which bends your arm at the elbow (fulcrum). This set-up isn't as strong as a second-class lever because here the effort is closer to the fulcrum.
Sometimes our levers are unable to function smoothly and efficiently due to muscles that are too tight or not aligned. Take a load off. Improve your leverage by seeking regular soft-tissue self-care such as a stretching routine combined with therapeutic massage. A combination of the two can help your joints move more smoothly and efficiently through a greater range of motion.