Injuries, Kinetic Chains and Weakest Links

I want you to imagine a packer at a supermarket. In front of him is a trolley filled with tins of jam. His job is to lift each tin and place it on a shelf that is roughly at shoulder height. This he does week in and week out, primarily using his bicep to lift each can. He is involved in a minor accident one day and injures the bicep, thus making his job more difficult. Now instead of using the bicep, which is ideally suited for his job, he needs to use his shoulder muscles to move the tin upwards. These muscles are not angled correctly for the job, and are therefore less efficient and require more effort. Within a few days his body fails him- his shoulders ache, and he develops a headache.

The example of the packer is played out daily in the world of endurance sport. Let’s take a runner for example. Running is a culmination of millions of nerve impulses and hundreds of muscles all firing to move the human body forward. Muscles in the feet, calves, upper legs, glutes, lower back, upper back and shoulders all need to join together in symphony-like order. If one of these goes wrong we end up in trouble.

Here is a typical example: take a runner who spends a lot of his working day sitting. Over time, his hip flexors shorten. The hip flexors help swing the leg forward. With shortened hipHipFlexor1 flexors our runner takes to the road. His hip flexors make it difficult for him to extend his leg fully backward as he runs. This difficulty brings about an adaptation in his run. He no longer uses his powerful glutes to drive his leg backward. Over time his glutes become weak. In order to move forward he now uses his quadriceps more and thus swings his leg too far forward resulting in a massive heel strike.  Our runner now places excess strain on his feet, knees, lower back, shoulders etc.

The runner with shortened hip flexors has managed to adapt his running style. One group of muscles is working much harder than the rest, and so,over time, a break down will occur. A weakest linkkinetic chain has been tugged once too often and has snapped at the weakest link. The injury could be in the form of a stress fracture, plantar fasciitis, runner’s knee, ITB, lower back pain, and so on, and so the shortened hip flexor shows up in the form of a seemingly unrelated injury.

How does one avoid incidents like this?

  1. Make sure that tight muscles are stretched.
  2. Make sure that all muscle groups are working. Each muscle has a muscle on the opposite side that does the opposite of its neighbour. Hamstrings pull your lower leg backward; quads pull your lower leg forward. Strength imbalance will cause problems.
  3. Go for a regular massage. An overworked muscle will show up under the thumbs of the massage therapist. These at times feel like ropy sections, or like small knots. The knot can be as small as a pea or as large as grape. This will give a clear warning that a part of the body is working too hard. Remember the shelf packer.
  4. Try to find the source of the problem. Karel Lewit said this, “He who treats the site of pain is lost.” Be aware of the therapist who simply dives into the source of the pain without considering where it comes from.
  5. Runners: make sure that you are in the right shoes for your running style. The shoe will make a difference, but remember, you cannot blame the shoe when there is a muscle imbalance.
  6. Cyclists: make sure that your bike is properly setup. An incorrect setup will mechanically induce an imbalance which can affect your knees and lower back.
  7. Swimmers: work on your swim style. You want to glide through the water, not fight it.

Feel free to give us a call if we help. We do runners leg assessments, bike setups and massage.


Mike Roscoe.

Mike Roscoe

About sbrsport

SBR Sport specialises in Swimming, Biking and Running. On the medical side we are able to do intensive bike setups, leg assessments and soft tissue release. - and/or facebook -
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