“Don’t contract your glutes.”
I’ve heard this instruction many times from yoga teachers, especially during backbending poses, but it’s always puzzled me.
The gluteus maximus – the large muscle of your buttocks — is the prime mover in actions that require hip extension against gravity, such as climbing stairs or standing up from a squat. It’s normally active in backbends such as shalabhasana (locust), setu bandhasana (bridge) or urdhva dhanurasana (wheel).
If the head of your thigh bone, or femur, rubs against the rim of your hip socket, or acetabulum, it can cause irritation and pain. Most often, it impinges against the front of the socket, which can create groin pain during deep hip folds. Femoroacetabular impingement can lead to osteoarthritis as well as tears of the labrum, a collar of cartilage around the rim of the acetabulum.
In the Times article, author William Broad claims that the syndrome is more common among women, particularly loose-jointed yoginis, than among men. That’s debatable. Many men, especially athletes, also experience femoroacetabular impingement, although the type of impingement typically differs in men and women.
However, Broad’s primary point — that excessive movement in the hip joints contributes to femoroacetabular impingement — is probably true.
As your hip joint flexes and extends (or, in English, bends and straightens), the femoral head should remain centered in the socket. To stay centered, it must glide backward a little when you flex your hip and forward when you extend your hip.
Many flexible yoga practitioners live in hip extension, habitually standing with the pelvis pushed forward, hanging on the ligaments of the hip, while the trunk tilts backward as a counterweight.
If you repetitively over-extend your hip, you’ll overstretch the front of the joint and compress the back of it. Do this enough, and you’ll restrict the normal backward glide of your femur during hip flexion, allowing the femoral head to migrate forward in the socket where it can impinge on the front of the acetabulum.
In other words, although you might feel the pain as a pinching at the front of the hip when you fold forward, the real cause could be how you extend your hip.
What does this have to do with using your glutes in backbends?
Because the gluteus maximus attaches to the upper femur, it’s well positioned to control the movement of the femoral head in the acetabulum. By pulling back on the femur during hip extension — such as when you’re lifting into bridge — it prevents the femur from pushing too far forward and over-stretching the front of the joint.
Yoga teachers who advise not contracting the buttocks during backbends often tell students to use the hamstrings instead. Like the gluteus maximus, the hamstrings are hip extensors, so that seems to make sense.
However, unlike the gluteus maximus, the hamstrings don’t attach to the upper femur. They run from the pelvis to the lower leg, bypassing the thigh bone.* This means they can’t stabilize the femoral head in the way that the gluteus maximus can.
Could habitually relying on your hamstrings instead of your glutes to create hip extension encourage femoroacetabular impingement? I don’t know of any research that’s looked at this, but it seems plausible, especially for people whose hip joints are already hypermobile.
Plausible enough to question whether it’s a good idea to tell students to avoid contracting the glutes in backbends – particularly when doing so means overriding the nervous system’s normal pattern of muscle firing.
So should I squeeze my glutes? All the time?
Not so fast. Chronically gripping your glutes doesn’t make any more sense than intentionally not using them. In fact, contracting your glutes when they normally wouldn’t be engaged, such as when you’re standing, could also lead to habitual hip hyperextension.
However, the bigger issue is: does it even make sense to micromanage movement by consciously contracting — or not contracting — particular muscles?
Most of the time, I don’t think so.
Motor control is a complex process, with many areas of the brain communicating to determine which muscles fire at which time. Most of that coordination happens below the level of conscious thought. The conscious part of the brain sets goals and coordinates the overall strategy, like the CEO of a company.
If the CEO goes down to the factory floor to tell the workers how to do their jobs, he’s more likely to mess things up than to help.
In the same way, consciously contracting or relaxing particular muscles is unlikely to improve how you move. The unconscious part of your brain already knows how to do that much better than you do.
I rarely use such cues when I’m teaching. They’re useful for some purposes, such as when you’re trying to strengthen a particular muscle. But I don’t think they’re generally helpful as a way of teaching movement. And, as with the glutes and hip pain in yoga, sometimes they could be harmful.
*The short head of the lateral hamstring, the biceps femoris, attaches to the lower part of the femur, but it only affects the knee joint, not the hip joint.
Urdhva dhanurasana by Joel Nilsson (Carrie -Yoga shoot #002 Uploaded by High Contrast) [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons
Anatomy of the hip joint by Smith & Nephew (Smith & Nephew) [FAL], via Wikimedia Commons