When it comes to overuse injuries of the hip, it is really easy to see each as a unique injury. The problem with that rationale is that overuse injuries are not the same as an acute, traumatic injury that resulted from a crash or fall. Overuse injuries are the result of mechanical problems that started small and worsened over time. The initial problem could have been simple- a sore, tight muscle that didn’t loosen up during recovery. Over time, that tight muscle leads to mobility loss at a joint. The only way to work around it is create that mobility elsewhere. This is known as compensation. It is the bodies way of creating a work around to keep us moving forward. It is also asking the body to work in ways that are less efficient and less sustainable over time. Eventually something will break down from the increased strain, causing injury. This is particularly true for the hip which is the top of the leg chain. Injuries here can be hard to get rid of because they are almost always a result of problems down stream in the leg.
As you can see in the picture above, there are A LOT of areas that can cause problems in the hip. The hip is home to the largest power muscles (i.e. the glutes), but they are also some of the last to kick in as we walk and run. Prior to this, the lower leg and thigh do all of the work to shock absorb and then stabilize the leg and body so that we can actually get to the bigger muscles. This creates opportunity for little things to add up and cause big problems. Let’s go joint by joint and break down what is required of them, as well as, what can go wrong.
Foot and Ankle
- Mobility requirements: full ankle dorsiflexion (ability to pull foot/toes up towards shin) and good toe extension.
- Why is this important: Having normal mobility in the foot and ankle is key to normal gait/locomotion. When the foot first hits the ground, it’s primary goal is shock absorption. As it adjusts to terrain and impact, it then stabilizes to create a strong platform to push off of. This takes time on your foot to allow that change to happen. If you run out of motion at the ankle or toes, it will shorten that time and subsequently the stability the foot and ankle provide.
- Other factors that can affect foot/ankle function: excessive pronation/supination in the foot. As we weight bear on our feet, we load the arches in sequence, rolling from the outside of the foot to the inside. This requires strength, mobility and muscle balance to guide the motion. If the foot over-pronates or supinates, it dramatically changes that process, limiting the ankle in the process. Shoe selection can make this effect worse. If the shoe provides too much support, it jams the ankle, blocking dorsiflexion. Likewise, too little support, allows the foot to collapse into pronation, forcing you to get off the foot before it is stable.
- Mobility requirements: Full knee extension (ability to straighten your knee fully).
- Why is this important: The knee is our middle man. Not only does a straight knee give us stability in mid stance, it also supports us as the workload shifts from the front of the leg to the back of the leg. If we are lacking mobility, it will limit that process and our ability to get to the big hip muscles. This means compensation as we look for alternatives to make up for the lack of glute activity.
- Other factors that can affect knee function: As the middle man, the knee is also home to large muscle groups that move both the knee and the joint above/below. For example, the hamstrings and gastroc (large calf muscle) criss cross behind the knee. Limitations in one, will affect the other. Likewise, the most superficial quad muscle crosses the hip joint. Limitations here will limit how far you can extend the hip back behind you.
- Mobility requirements: Full hip extension.
- Why is this important: The glutes main function is to extend the hip. If you are lacking the mobility to do so, all the strength work in the world won’t change that.
- Other factors that can affect hip function: In addition to flexion and extension, the hip also rotates (internally and externally). As we walk/run, the entire femur rotates to assist with those movements. This requires good mobility and balance in the small, rotator muscles in the front and back of the hip. If there are problems down stream, compensation typically involves this rotation getting out of balance. This makes it harder for the hip to move forward and back as you are constantly trying to correct that over rotation. Over time, the excessive rotation can cause impingement at the hip itself. Over time this jam at the hip can progress to the point where you need to hike the whole hip up to swing your leg through.
- While it’s harder to visualize, the pelvis is capable of rotating forward and back. This is called anterior and posterior tilt and is controlled by our core stability. As we move forward, our core is what holds our trunk upright and provides the stability to maintain or center of mass.
- Other factors that can affect our pelvic alignment/stability: soft tissue restrictions in the front and back of the thigh. More specifically, chronically tight hamstrings can pull the pelvis back into a posterior tilt while chronically tight hip flexors can keep the pelvis stuck in an anterior tilt. Both change how we hold our center of mass, as well as, the natural alignment of our spine.
So why are we talking about all of these areas instead of just the hip itself? As we move forward through the individual hip courses and the different types of injuries we typically see there, we will be addressing all of these areas to restore balance to the entire leg chain as a whole. In the mean time, let’s take a quick look at how you stack up on the mobility front!
Hip Extension: Lying flat on your stomach, keep your hips flat, tighten your glutes and lift your leg up straight without using your back or shifting/rolling onto the other leg.
2) Knee Extension: Sitting with your legs out in front of you, push the back of your knee into the floor and lift your heel up.
3a) Ankle Dorsiflexion: With your foot flat on the floor and your heel down, move your knee over your toes.
3b) Toe Extension: With the ball of your foot flat on the floor, bring your foot over your toes.