This article originally appeared in the May/June 2016 Issue of UltraRunning Magazine
Throughout 2016, we have analyzed the fundamentals of efficient running mechanics and how the demands of the ultra distance impact our run. Last month, we discussed arm swing. This month, we address the powertrain – the hips.
A vehicle’s powertrain is the mechanism that transmits energy from the engine to the ground. Likewise, the hips transmit our metabolic power from the trunk, through the legs to the ground, providing the true propulsion of running. The other musculature – in the feet and ankles, shins and thigh – are mere accessories to the running action. The hips drive all.
What is ideal hip drive?
Very simply, the role of the hip is to provide a rearward and downward push and an upward and forward drive. These are reciprocal actions: the rear-and-down push counterbalanced by the up-and-forward drive. This motion occurs in the ball-and-socket hip joint: with the gluteals and iliopsoas muscles being the prime movers of push-off and forward drive, respectively. When the hip moves, the other joints of the leg – the knee, ankle and foot – follow suit, all doing the same thing: flexing up and forward, and extending down and behind, to propel the body forward.
Ideal hip drive is:
- a knee and thigh that lifts a bent leg forward, nearly to the waist, and
- a nearly-straight leg that extends equal to – if not slightly past – the trunk
In fact, this reciprocation of the driving-forward and pushing-rearward thighs, called hip separation, is the gold standard for running efficiency. At any given speed, the greater the angle of hip separation, the more powerful, efficient and less stressful running will be.
Efficient hip drive is surprisingly simple and compact. Yet it is a challenge to nearly every runner, because it takes surprising amounts of awareness and strength to maintain. Failure to use the hips efficiently results in compensatory strategies. And while compensations may keep us upright, they come at a cost.
What is it not?
An integral part of hip drive is trunk alignment. As outlined in the January issue, a “tall-and-forward” trunk alignment naturally positions the hips to push the leg behind the trunk. However, fatigue and terrain factors can alter that alignment, severely hampering hip power.
If the hip muscles cannot drive the trunk forward, the body must compensate to generate propulsion force:
- above the hip, the low back will over-arch, in order to push the trunk beyond the leg
- the hamstrings will over-work to pull the thigh behind the trunk
- the quads and calves will attempt to push the trunk by extending the knee and ankle, respectively
These actions are all minor accessories to an efficient stride. But absent the prime hip movers, the powertrain is corrupted: the engine is only firing on a few odd cylinders.
Benefits of powerful hips
The hip and core musculature comprise the biggest, strongest muscles in the body. Indeed, when it comes to both size and force production, the gluteus maximus – the hip extender – reigns supreme. More importantly, these muscles are indefatigable: working together, they will never cramp. On top of that, strong, efficient hips limit impact stress to the system. The better the hips are utilized, the less muscle and joint stress is incurred.
More speed, less stress equals fast running and quick recovery. One need only to look at the sport’s fastest runners for proof: the best ultramarathon runners use their hips like track stars, running faster and incurring less impact strain.
Trail and Distance Challenges. If activated hips require forward trunk alignment, then core stability muscles – responsible for keeping the trunk tall-and-forward – play an enormously important role in maintaining hip power.
A stable core creates a strong platform, off which the glutes push and hip flexors pull. If the trunk lacks stability, hip power is lost. Two good analogies highlight this concept: for the glutes, imagine a cannon firing from a canoe; for the hip flexors, imagine a rope connected to a marshmallow wall. In both cases, the lack of a strong, stable base severely impacts push-and-pull power!
Ultra-distance fatigue affects both trunk stability and orientation. With fatigue, the core softens, the trunk shifts upright, or loses alignment, and hip power is compromised.
Absent strong hips, the lower muscles – the quads, calves, hamstrings and adductors – must over-work to push and pull us along. These groups are prone to mid-race cramping, and the dreaded “blown quads” phenomenon – both race-stoppers. Conversely, you will rarely hear of a runner complaining of cramping or trashed glutes!
Elevation changes challenge hip power. Loading the hips requires a forward trunk, and too often a steep up- or downhill shifts the trunk upright. Moreover, runners will often “ease off” assertive forward engagement and assertive hip drive on technical terrain. Upright, tip-toe running shuts off the hips.
Gear Challenges. As with the trunk, hydration systems impact both trunk and hip engagement. Any system that impacts trunk engagement and alignment can jeopardize hip power. Any gear around the waist can restrict hip mobility: possibly blocking full extension, or hindering forward lift.
It’s cliché but true: it’s all in the hips! Use them well, and they’ll take you far!