Hip issues in sports have become much more prevalent in recent years, along with an exponential increase in hip surgeries. We are seeing more athletes training around hip/groin injuries and rehabbing post hip arthroscopy.
I recently read a systematic review that concluded that core strengthening was an integral part of management of FAI prior to surgical interventions.1Although they did not define core strengthening, I believe this brings up an important conclusion. Here are 3 reasons why core strengthening is important for hip rehab.
Pelvis position
The position of the pelvis has a large influence on the hip. Research has suggested that even as small as a 10oanterior pelvic tilt will cause significant changes at the acetabulum and femur. A simulated anterior pelvic tilt of 10oon radiograph led to significant relative retroversion of the acetabulum, an almost 2x increase in percentage of patients with a cross over sign, posterior wall sign, and prominent ischial spine sign. Also, 73% of patients without a cross over sign in a neutral pelvis position had a positive cross over sign with a 10oanterior tilt. This change in pelvis position also demonstrated decreases in hip range of motion and early impingement. In the same study with the same participants, with a 10oposterior tilt, the number of participants showing the same signs of acetabular retroversion was cut in half, while also resulting in increases in hip ROM and later femoroacetabular contact.2
If the pelvis is in a poor position, the hip will not be able to function optimally. This can often be the origin cause of hip issues. Vladimir Janda coined the well-known “lower cross syndrome” suggesting that the lower abdominals are long and weak. Based on Janda’s work, strengthening the lower abdominals, internal obliques and external obliques (along with correcting other weaknesses/limitations) would posteriorly tilt an anteriorly tilted pelvis and better align the pelvis for optimal hip function.
Proximal stability for distal mobility
This idea of proximal stability for distal mobility has been taught by many different great movement specialists. I think this on its own shows the importance and validity of this concept. For those who haven’t heard of proximal stability for distal mobility, it’s the idea that the joints above need to have the ability to stabilize in order for the joints below to move well. A prime example is core stability for hip mobility. Dean Somerset shows the ability of core stability to increase hip mobility in this video (prepare to have your mind blown!). I also like to think of it like shooting a canon out of a canoe. Without a stable base, when the canon fires, it’s just going to push the canoe backwards. When the core can’t stabilize, the hip needs to create more stability to create a base to move from. This often leads to compensations and muscle imbalances at the hip like tight hip flexors, tight hamstrings and tight hip rotators. Researchers have also demonstrated that a 6-week core endurance program led to improvement in hip internal rotation and total hip rotation without doing any stretching.3
Energy transfer for optimal performance (especially in rotation sports)
When returning an athlete to sport after injury, we need to make sure they are able to meet the requirements of the sport. In most sports, player must produce some form of power from the lower extremity and transfer to the upper extremity(ies). In order to optimally do so, they need to transfer as much energy as possible, without losing much. Having a stable core helps transfer the majority of that energy. For example, baseball players need to be able to transfer power from the legs, up through the trunk and to the arms in order to produce a powerful swing. Think of it as hitting the cue ball in pool, where the energy from the cue ball is transferred to the other balls to make them move. The harder you hit it, the harder the other balls move. This is the energy transfer with a stable core. Now imagine playing pool with balls made of sponge. Not very effective. This is energy transfer with a weak unstable core. So if we ignore training the core after rehab, players will be playing with the sponge balls instead of the actual pool balls.
Conclusion
Although these players often present with hip issues and symptoms, the core can play a large factor in the origin of these issues. Researchers have suggested that core strengthening should be a component of any hip rehab because it allows the pelvis to be in a better position for the hip to perform optimally and for better on field performance when the athlete returns to sport.
References
- Hoit, G., Whelan, D. B., Dwyer, T., Ajrawat, P., & Chahal, J. (2019). Physiotherapy as an Initial Treatment Option for Femoroacetabular Impingement: A Systematic Review of the Literature and Meta-analysis of 5 Randomized Controlled Trials. The American journal of sports medicine, 0363546519882668.
- Ross, J. R., Nepple, J. J., Philippon, M. J., Kelly, B. T., Larson, C. M., & Bedi, A. (2014). Effect of changes in pelvic tilt on range of motion to impingement and radiographic parameters of acetabular morphologic characteristics. The American journal of sports medicine, 42(10), 2402-2409.
- Moreside, J. M., & McGill, S. M. (2012). Hip joint range of motion improvements using three different interventions. The Journal of Strength & Conditioning Research, 26(5), 1265-1273.