WHAT IS THE KINETIC CHAIN?
In (extremely) simplistic terms, your body is made up of parts that act like a system of chain links. When you move, energy or force generated by one link (or part of the body) needs be transferred successively to the next link if we are to move efficiently.
Looking at the lower half of the body, the foot, shin, thigh, pelvis and lower back act as links in the chain. They are given mobility by joints of the ankle, knee, hip, pelvis and spine, and rely heavily on one another for effective and efficient motion.
Just like the chain on a bike, efficient movement requires sufficient mobility between the chain links and enough strength in all parts of the chain. Both stiff and weak links in that chain can lead to inefficient movement or complete breakdown of the chain.
STIFF LINKS
As mentioned above, we can develop stiff links and weak links within the kinetic chain. Both can create problems upstream or downstream.
A stiff link in the chain tends to cause compensatory excessive movement elsewhere in the chain. And that excessive movement creates abnormal stress and strain. That’s why the stiff link may be the original cause of problems, but the relatively flexible link in the chain is frequently the source of pain and pathology.
For example, someone who sits down all day can develop tight hip flexors. Tight hip flexors lead to reduced hip extension, which in turn may cause excessive movement in the lower back and pelvis, leading to low back pain. The problem was the tight hip flexors, but the weak link in the chain (the lower back) is the area that becomes painful.
WEAK LINKS
Similarly, a weak link can create problems elsewhere in the chain.
For example, a runner with a weak gluteus medius muscle (the side-glute) will often collapse their hip as they land. Sideways collapse of the hip can cause an increase in tension along the outside of that leg, particularly over the Iliotibial band (ITB), which can create tension over the side of the knee. This can lead to ‘ITB syndrome’ at the knee.
In this instance, the problem was the weak gluteus medius muscle, but the victim was the outside of the knee.
THE MISSING PIECE: HOW YOU MOVE
Unlike a simple chain-link, the links of the body are controlled by a rather amazing supercomputer, the nervous system, which controls the coordination and timing of our movement.
And unlike a machine, the human body is very good at compensating for weak and stiff links. This usually involves adopting suboptimal/ dysfunctional movement patterns, which unloads the affected areas.
You can usually manage just fine with these faulty movement patterns so long as you don’t try to do anything too strenuous. However, movement dysfunctions tend to place a glass ceiling on your physical capabilities. As soon as you push hard, perform repetitive movements or adopt sustained postures, you’ll be more prone to injury.
So once you’ve identified and set about treating weak and stiff/ tight links in the chain, you usually need to re-learn new, functional movement patterns to replace the old, faulty patterns.
THE RIPPLE EFFECT
So how far up or down the chain do we need to investigate to find the original cause of pain and pathology?
Problems in one area tend to ripple upstream and downstream through the body. Like ripples on a pond, the effect tends to be strongest closest to the affected area and get weaker further away from the primary problem.
A painful, stiff or weak hip will often lead to low back pain (upstream) or knee pain (downstream). It’s less likely to lead to neck pain or ankle pain, but even that’s a possibility, so it’s useful to assess areas far removed from the primary area of concern.
SO, HOW CAN YOUR PHYSIO HELP?
Sometimes it takes an experienced pair of eyes to identify faulty movement patterns and relevant stiff and weak links up and down the kinetic chain.
The more thorough your assessment, the larger number of movement dysfunctions, stiff links and weak links that can be identified, and the greater number of treatment options that are available. One of those could be the vital piece of the puzzle when you’re trying to overcome persistent, long-term problems.