In my previous article I discussed the role of the hip flexors in musculoskeletal dysfunction. The knock on effect of chronically tight hip flexors are numerous but two very important ones, which I only touched on last time, are weak under activated gluteal muscles and hamstrings that become dominant in hip extension.
The Gluteus Maximus is the main hip extensor in the body. Attaching from the ilium, sacrum and coccyx it inserts into the outer aspect of the hip. It’s needed in nearly all movements. The gluteals also bring about stability of the Sacro-iliac joint via its influence on the thoracolumbar fascia and the posterior fascial slings.
Although the hamstrings also influence the hip into extension the Gluteus Maximus is the main player in this movement.
Hamstring dominance is when the Gluteus Maximus doesn’t initiate hip extension, instead leaving the work to the hamstring muscle.
But why does this happen?
The mechanism behind this is called reciprocal inhibition, where a tight / over activated muscle inhibits its antagonist. In this case the over activated and tight Hip flexor inhibits the activation of its counter part, the Gluteus Maximus. In doing so the hip extension movement pattern, over time, has become initiated by the hamstring instead of the Gluteus Maximus.
Not only can this lead to an overuse strain of the hamstrings but due to the Gluteus Maximus’ key role in spinal stability it increases the chance of injury to the lumbar spine and sacrum.
Hamstring dominance can be tested for with the patient prone and asking them to actively extend the leg. Not always easy to see with the naked eye, feeling the hamstrings and Gluteus Maximus muscles during the active hip extension can be quite revealing. The Gluteus Maximus should be the first to contract followed by the hamstrings but with hamstring dominance its the other way around.
How do we get the Glutes firing again:
Gluteal activation exercises are well documented but often under utilised. To become hamstring dominant the neuromuscular pathway needed for hip extension has been re-learnt using the wrong muscle group. So to re-establish the correct movement pattern this neuromuscular link is best established through repetition. Addressing the tight hip flexors with stretching is important but strengthening of the Glutes will also be needed. As mentioned in the last article the main four I encourage patients to focus on are
2.Quadruped Hip extensions
3. Single Legged Bridges
4.Standing functional reaches
Performing these regularly in isolation will encourage the Gluteus Maximus to take back its role as the primary hip extensor. Performing these as part of a warm up before weight lifting, running or sporting activities is a great way to re-establish the neural pathways that have been lost over the months or years of deactivation.
This doesn’t sound like chiropractic?
Some may think that the topics I write about aren’t chiropractic but I certainly don’t agree with that. As a chiropractor I am concerned with the function of the neuro-musculoskeletal system which includes the relationships between the nervous system, muscles and joints. Having an understanding of the chronic repetitive nature of many of the presenting complaints allows the cause of the problem to be addressed rather than purely the symptoms. And if this understanding means using research and techniques devised by physiotherapists, osteopaths and chiropractors then that’s what I’ll do.
You can find a handout on these glute activation exercises in the ‘Material for patients’ tab at the top of the page.