PT on the Net Research

Developing Single Leg Stability


The development of single leg stability is potentially the cure-all for many of the chronic lower extremity problems seen today. Numerous clients suffer with knee problems such as chondromalacia patellae, patellar tendinitis or other patella-femoral syndromes. Most often, these problems are attributed to problems with the knee joint itself or with the patella. Frequently, therapists will describe these problems as patella tracking issues and recommend limited range strengthening for the quadriceps. Although this is an outdated concept, many therapists still cling to these outdated ideas. My experience has taught me that most clients suffering from chronic knee pain generally share a common difficulty in stabilizing the lower extremity while performing a single leg squat. This inability to stabilize is actually a hip dysfunction related to an inability to properly fire the glute medius (a neuromuscular control issue) or an actual weakness in the glute medius (a strength issue).

Until recently, many viewed my thoughts on this subject to be opinion. However, recent research has validated what was once a hypothesis. A study by Ireland et. al. and research by Powers has validated the hypothesis in an academic setting. Ireland states, "In the absence of sufficient proximal strength, the femur may adduct or internally rotate, further increasing lateral patellar contact pressure. Repetitive activities with this mal-alignment may eventually lead to retropatellar articular cartilage damage generally associated with this syndrome." Ireland concluded that healthy subjects had normal strength while the subjects with patella-femoral pain had significant weakness. Although all subjects in Ireland’s study where female, I believe that the same results would be seen in males with patella-femoral pain.

Noted physical therapist Gary Gray has advocated attacking knee pain from “the hip down” since the early ‘90s, but many in the field are slow to change. In many clients, the muscles that control the hip are either too weak to perform their function or are not “turned on” neurologically. As a result, the support structures of the knee are forced to provide stability instead of the gluteus medius. This may mean pain in the ilio-tibial band (IT), in the patellar tendon or under the kneecap. In order to better “turn on” the glute medius, bands below the knee joint can be used in double leg squatting (see Figure 4.13) and in some single leg variations (see Figure 4.14).

Figure 4.13 Bodyweight squat w/ Theratube Figure 4.14 1 Leg Squat w/ Theratube

The gluteus medius is an often neglected muscle of the hip whose primary function is to stabilize the lower extremity in single leg movements such as running, jumping or squatting. As stated previously, these problems were frequently blamed on poor quadriceps strength, and doctors and therapists prescribed simple, non functional exercise like leg extensions to solve the problem. Recently, therapists and athletic trainers have begun to recognize the role of the gluteus medius in these knee problems. Correction involves facilitation of the glute medius as mentioned previously as well as single joint isolation exercises to teach athletes how to use the gluteus medius and to promote simple strengthening. Two simple exercises, the bent leg hip abduction and straight leg hip abduction, are used for this purpose. These exercises have been proposed by physical therapist Shirley Sahrmann in Diagnosis and Treatment of Movement Impairment Syndromes.

Bent Leg Hip Abduction

To perform bent leg hip abduction, lie on the side with the knees bent 90 degrees and the hips flexed to 45 degrees. The soles of the feet should be in line with the spine. This position is like the hook-lying position (lying on the back with the feet flat on the floor and both the hips and knees flexed), only on the side (see Figure 4.15). The top shoulder and hip should be positioned slightly ahead of or in front of the bottom hip and shoulder. Abduct (raise) the leg, keeping the feet together without rotating at the lumbar spine. The hips and shoulders should remain in line one over the other, and all the motion should come from the hip. Generally, sets of 10 reps are done in week one, and two reps per week are added. Most clients with hip weakness will erroneously make this a trunk rotation exercise. Clients must abduct the thigh with no rotation at the lumbar spine. In order to facilitate this action, the client can be placed against the wall, or the trainer or therapist can stand behind the client with the lateral shin placed against the glute max. Whether the therapist uses his own leg or the wall, the instruction must be to abduct without pressing into the wall or the leg. The key is to make the motion one of abduction and external rotation, not lumbar rotation. In order to do that, the cue must be “lift your knee as high as possible without pressing against my leg."

Figure 4.15 Bent Leg Hip Abduction

Straight Leg Hip Abduction

Straight leg hip abduction is another exercise to facilitate and strengthen the glute medius (see Figure 4.16). This is also an attempt to isolate the muscle so it will function better in its role as a hip stabilizer. Mark Verstegen of Athletes’ Performance likes to call this process “isolation for innervation.” This concept goes back to the debate of single joint versus multi joint exercise. Many of the gurus of functional training may feel that only multi joint exercise is appropriate, but my theory is that isolation is fine for joints with high degrees of freedom (like the hip or shoulder) or for joints that need high degrees of stability (like the hip, shoulder or spine). Stay away from single joint exercises for the hinge joints (elbow and knee), and you’ll be enhancing function.

To perform straight leg hip abduction:

These exercises are valuable in helping athletes learn to isolate and activate the gluteus medius, but attention to detail is critical. It never ceases to amaze me that clients can find ways to cheat on even the simplest exercises. Another benefit to the straight leg hip abduction exercise is that it also recruits the lateral fibers of the external oblique muscle.

Figure 4.16 Straight Leg Hip Abduction Figure 4.17 Close Up of Foam Roller Above Iliac Crest

Straight Leg Mini-Band Walks

Straight leg mini-band walks may be one of the most underrated exercises in the functional training world. This is a classic “innervation” exercise. Many of the functional purists might dismiss this exercise because “you never walk with the legs straight.” I can only ask that you try the exercise before you dismiss it. As I have said previously, isolation exercises for joints with significant mobility or for joints that need additional stability are not only acceptable but desirable. The hip joint meets both of the above mentioned criteria. When performed correctly, the glute medius is directly affected like no other exercise.

To correctly perform straight leg mini-band walks:

Straight leg mini-band walks should be viewed as a strength exercise. Work your way up to Perform Better gray bands, and you will develop significantly greater function in the hip abductors.

Super Band X Walks

SuperBands from Perform Better can provide an even greater stress to the hip abductors while also activating the retractors and depressors of the scapula (see Figure 4.18).

This exercise borrows a concept from Physical Therapist Alex McKechnie. McKechnie utilizes Theraband to activate the diagonal “slings” of the body. The concept, which Thomas Meyers also alludes to in Anatomy Trains, is that the body functions in diagonal connections. The cross point of this connection is the lower back where tissue, known as the thoraco-lumbar fascia, acts as a connector from the lower body to the opposite side of the upper body. If this seems confusing, just imagine trying to shoot a right-handed lay up off of your right foot.

Figure 4.18 SuperBand X Walk

To perform the X Walks, stand on the Superband and grasp the right side of the band with the left hand and the left side with the right hand, creating an X. The client or athlete is instructed to pull the shoulder blades down and back and to proceed as in the mini-band walk. The X creates an adduction force that must be worked against while also activating the scapula retractors and depressors.

Reformer Straight Leg Abduction

If you have access to a Pilates Reformer, standing straight leg abduction is another excellent exercise to innervate and strengthen the glute medius. I actually like this exercise better than the mini-band walks but do not always have access to a Reformer. Simply stand on the Reformer with one foot on the base and the other on the pad and attempt to abduct. This exercise is especially difficult because momentum can be minimized and the spring resistance is increased in the end range.

Eccentric Single Leg Squat

The eccentric single leg squat begins to bridge the gap from isolated exercise to multi-joint exercise and will actually be cited again when single leg progressions are discussed. Eccentric single leg squats are excellent for any patella femoral pain patient. Patients suffering from patella femoral pain often experience difficulty during the transition from the eccentric contraction to the concentric contraction. Initially the eccentric single leg squat is done through a limited range of motion with no concentric contraction. How can this happen? Simple. The patient lowers for the prescribed time (see tempo) and then stands up with two legs. This is the pure eccentric only version. Eccentric single leg squats should begin with a small, pain free range of motion and along eccentric contraction (five to six seconds). This exercise literally teaches the glute medius and glute max how to re-establish control of the femur. Remember, knees don’t usually go bad. Instead, hips fail to properly and adequately control knees.

To further aid in controlling the femur, a band can be placed below the knees (see Figure 4.14) to provide a stimulus to the glute medius by creating an adduction force. The adduction force of the band at the knee will again “turn on” the glute medius through its role in abduction.

Don’t underestimate the power of simple exercises to have a big effect on your clients' health.

References:

  1. Cook, G 1997. Functional training for the torso. NSCA Journal(April): 14-19.
  2. Francis, C. 2000. Training for speed. Canberra, Australia: Faccioni Speed and Conditioning Consultant.
  3. Ireland,M et. al. 2003. Hip strength in females with and without patello-femoral pain. JOSPT (33,11, 671-675)
  4. McGill, S. 2002. Low back disorders. Champaign, IL: Human Kinetics.
  5. Richardson, C., G. Jull, P. Hodges, and J. Hides. 1999. Therapeutic exercise for spinal segmental stabilization in low back pain. London: Churchill Livingston.
  6. Sahrmann, S. Diagnosis and Treatment of Movement Impairment Syndromes
  7. Thibedeau, C. Theory and Application of Modern Strength and Power Methods
  8. Weiman, K Tidow, G 1995. Relative activity of hip and knee extensors in sprinting- implications for training. New Studies in Athletics ( 10,1, 29-49)