How many of you currently deal with clients and athletes with restrictions in hip motion? From the middle aged desk worker to the professional athlete, restrictions in hip motion are common in many individuals regardless of their activity level. While there are multiple causes of hip restrictions, a few of the more common ones include trauma (acute and repetitive), inhibition of the lumbo-pelvic core and pelvic floor, capsular restrictions and degenerative joint changes of the hip (osteoarthritis). Regardless of the aforementioned causes, limitations in hip rotation inevitably lead to compensatory movement patterns and place a strain on surrounding soft tissue and joint structures. The regions immediately above and below the hip complex are particularly vulnerable to changes in hip function. In fact, it is rare to see an individual complaining of low back or knee pain that does not have associated hip dysfunction.
There are over 20 muscles oriented around the hips and pelvis and many others in close proximity that are designed to stabilize, accelerate and decelerate rotation of the trunk and lower limb. Several of these muscular influences are listed in the table below. It is important to note that many of these muscles can change their function depending on the position of the femur in relationship to the pelvis.
|External Rotators of the Hip
||Internal Rotators of the Hip
||Anterior fiber gluteus medius
|Posterior fibers gluteus medius
||Tensor fascia latae
||Adductor magnus- oblique fibers
||Piriformis (during hip flexion)
It is also important to note that there are many muscles that do not directly cross the hip joint but have a dramatic impact on hip rotation. One example of this concept is the oblique abdominals. To demonstrate this, stand with your feet shoulder width apart and arms crossed over the chest. Rotate your trunk to the left and feel what happens to the hips. You should notice that there is external rotation of the right hip and internal rotation of the left hip. Therefore, inhibition or restrictions in either the anterior or posterior rotation chain will dramatically affect hip rotation on either side of the body. While discussing every single muscular influence on the hip is not the goal of this article, it is important to realize limitations in hip rotation can occur from areas that anatomically may be quite removed from the actual hip joint itself.
Muscular Control: Tonic and Phasic Muscles
Most muscles are comprised of both slow and fast motor units. Postural control and low level activities are controlled by slow motor units, otherwise known as tonic muscles. These muscle fibers are located closer to the axis of joint rotation and are recruited at low levels of effort. Under normal conditions, these fibers are resistant to fatigue. Fast motor units, also known as phasic muscles, are required for high level or rapid movements. These fibers are generally located further from the axis of rotation and are quick to fatigue.
The difference between these two fibers classifications can be demonstrated by looking at the gluteus maximus. The gluteus maximus is a large muscle originating from the posterior surface of sacrum, fascia of the gluteus medius, coccyx, sacrotuberous ligament and thoracolumbar fascia. It inserts proximally into the gluteal tuberosity and distally into Gerdey’s tubercle, lateral tibial condyle, fibular head and joint capsule of the knee via the iliotibial band. It is composed of both superficial and deep fibers. The superficial, lateral (phasic) fibers are responsible for extension, abduction and lateral rotation of the hip. The deep, medial fibers (tonic fibers) are responsible for extension and external rotation of the hip. More precisely, these deeper/medial fibers are responsible for pulling the head of the femur posteriorly in the socket, thereby maintaining an efficient axis of rotation. These fibers are also responsible for maintaining integrity and stability of the sacroiliac joint.
An all too common scenario occurs when there is inhibition of the hip stabilizer muscles. Inhibition (secondary to trauma, fatigue, over-use, etc.) of these deep, medial fibers leads to over activity of the synergistic muscles, mainly the superficial fibers of the gluteus maximus, hamstrings and lumbar erectors. In addition to causing sacroiliac and lumbar compression syndromes, an increase in hamstring activity to maintain postural control is one of the main causes of hamstring insertional tendonopathies and mid-belly hamstring tears. Most training protocols for these types of injuries (i.e., exercises such as bridging, stability ball hamstring curls and side lying clams or hip abduction) emphasize gluteal and hamstring strengthening. While there is some validity to this approach for some individuals, the typical effect of this approach is continued strengthening of the hamstrings and lateral fibers of the gluteus maximus. The result of these exercises is continuation of an altered axis of rotation, thereby altering muscle activation and timing sequences, which results in perpetuated faulty movement patterns.
Therefore, to improve hip function, attention must be given to the fibers that stabilize the femur in the socket and the sacroiliac joint, mainly the deep, medial fibers of the gluteus maximus. The remainder of this article will focus on specific strategies in which to activate these fibers and to restore the rotatory function of the hip joint.
Activation of the Deep Stabilizers
As mentioned, improving balance around the hip joint includes restoring the integrity to the tonic fibers of the gluteus maximus. Why focus on the deep stabilization system? Work by Hodges et.al. has demonstrated a timing delay (feed forward mechanism) in the transversus abdominus (TvA) in individuals with low back pain. Hodges demonstrated that in individuals with no low back pain, activation of the TvA preceded limb motion. However, in individuals with low back pain, limb motion preceded activation of the TvA. They also found that the TvA became direction-specific (as opposed to working through any direction of trunk or pelvic motion) and the contractions tended towards phasic activity rather than maintaining tonic control. In individuals experiencing low back pain, dysfunction has also been demonstrated in other stabilizing muscles of the core including the multifidus. Hungerford has demonstrated atrophy of the multifidus after even one episode of low back pain. Similarly, individuals experiencing chronic hip pain tend to demonstrate patterns of atrophy in the deep stabilizing fibers of the gluteus maximus. These findings support the need for improved motor control and specific training of the deep stabilization system in order to restore both the timing of muscle sequencing as well as the proper control around the hip joint.
Activation of the deep fibers requires precision in cueing and muscular control. The goal is to activate these deep fibers with no contribution from the superficial fibers and maintain this activation while performing diaphragmatic breathing. The individual begins by lying on his stomach with the legs straight and the forehead resting on the forearms. The individual begins diaphragmatic breathing while relaxing the hip region completely. The individual then visualizes a line between his ischial tuberosities and activates the deep gluteals. The effort should be about a 10 to 25 percent of maximum contraction and he should maintain this contraction for 10 seconds. The goal is to work up to 10 sets of 10 second holds while breathing and maintaining a low level of contraction.
Once the basic version is mastered, the client is progressed to prone hip rotations. The client maintains the prone lying position and bends one knee to 90 degrees. The thigh should remain in line with the body throughout the movement. The client activates the deep gluteals and rotates the hips medially and laterally. He should perform 10 to 20 reps at a slow to moderate pace while maintaining activation of the deep gluteals. Repeat on the other side.
Performing standing split stance hip rotations increases the functional carryover of this exercise and teaches closed chain hip-pelvis dissociation. The client is instructed to stand in a split stance, one leg forward and one leg back. The legs are approximately shoulder width apart and the hips, knees and ankles are held in straight alignment. There should be a slight bend in both hips, knees and ankles while the shoulders, hips and pelvis should be level. The client is instructed to activate the deep gluteal muscles, and while maintaining this contraction, the pelvis is rotated around a stable leg. The motion should be completely from the hip, and there should be no movement of the lower leg or spine. Perform internal rotation by rotating the pelvis toward the forward leg and external rotation by rotating the pelvis away from the forward leg.
The modified split stance with trunk rotation is an excellent way to train stabilization mechanics in the lower extremity while subsequently training trunk rotation. Begin in a split stance position (as wide as the individual can control) with the arms held at shoulder height or level with the floor. Rotate the trunk towards the side of the forward leg (internal rotation of the hip - see Figure 1 below). Return to beginning position and repeat to the opposite side (external rotation of the hip - see Figure 2 below). Rotation should occur on a constant axis with no shifting in the spine while simultaneously maintaining the alignment in the ankle, knee, hip and pelvis. Ensure core activation throughout the motion. If the client has difficulty maintaining balance and/or stability, shorten the length of the stance and/or the amount of trunk rotation.
Figure 1. Split Stance with Internal Rotation
Figure 2. Split Stance with External Rotation
The single leg rotation is the next progression. The individual stands on one leg and activates the deep gluteals. The shoulders and pelvis should remain level and alignment should be maintained between the hip, knee and ankle. Maintaining contraction of the deep, medial gluteals, rotate the pelvis away from the stance leg while maintaining the alignment of the leg. Return to neutral and repeat for as many repetitions (up to 10) as the individual can maintain alignment of the pelvis and legs. It is important that alignment is maintained during the entire range of motion as compensatory stabilization patterns are encouraged as the quality of the movement patterns diminishes.
Limitations in hip rotation can often be attributed to muscular imbalances within the movement and stabilization systems of the lumbo-pelvic-hip complex. Restoring hip rotation requires specific training aimed at restoring activation of the deep, stabilizing fibers of the gluteus maximus. By activating the deep, medial gluteals and following the proper progressions, rotation can be enhanced in most clients regardless of the cause of their restrictions and the goals of their training.
- Comerford, Mark. Mechanical Stability Dysfunction of the Hip and Lower Limb, Course Handouts, 2006.
- Osar, Evan. Complete Hip and Lower Extremity Conditioning, Form and Function, Chicago, 2005.
- Osar, Evan. Form and Function- 2nd Edition, Form and Function, Chicago, 2005.