Jan 29, 2015Best Foot Forward
Designing single-leg training programs means more than targeting specific muscles. It requires evaluating the athlete and using a whole-body approach.
Jeremy Boone and Gray Cook
Jeremy Boone, CSCS, NMT, USAW, is the owner of Athlete by Design in Charlotte, N.C. He has worked with several professional sports teams, including the Carolina Panthers, and can be reached at: www.athletebydesign.com.
Gray Cook, MSPT, OCS, CSCS, creator of the Functional Movement Screen, is Clinic Director at Orthopedic & Sports Physical Therapy in Danville, Va. He can be reached at: www.functionalmovement.com.
Single-leg training has received a great deal of attention in injury prevention, rehabilitation, and performance-enhancement programs over the last few years, and for good reason. Since the athletic movement skills of field and court sports are dominated by the gait cycle—taking off from one foot and landing on the other—single-leg training is appropriate for return-to-play programs and boosting athletic performance.
Unfortunately, the benefits of single-leg training have led some people to adopt it as a “one-size-fits-all” approach to lower-body development—without really thinking about the purpose the exercise serves within a training program. Too often this leads to a goal of building a selected muscle instead of improving overall athletic performance.
However, there’s an alternative to blindly integrating single-leg training into workouts. And it starts with identifying the specific needs of the individual athlete. If you want to improve lower-body performance, you must first think globally, then act locally. Rather than counting on a standard set of exercises, evaluate the athlete to determine what he or she needs. Then, choose the exercises that can best provide it.
Isolation Frenzy
A popular approach among those using single-leg training is to target individual muscles, and much recent attention has been focused on the gluteus medius. This muscle plays a key role in pelvic stabilization and preventing low back pain, and it can certainly be a trouble spot when it’s too tight or not strong enough. As a result, a number of isolated exercises, such as bridge patterns targeting this muscle, are being prescribed to athletes whether they’re needed or not. Without knowing the quality of the movement patterns involving this muscle, results are second rate at best. In fact, we may find ourselves training the gluteus medius to improve the lunge pattern rather than improving the lunge pattern to train the gluteus medius.
Another hot spot in single-leg training is the psoas muscle and its ability to flex the hip joint, decelerate hip extension, and stabilize the lumbar spine. Yet again, a common practice is to target this muscle by providing a blanket prescription of exercises for every athlete. Often this prescription comes after just a quick test or two. In one typical test of the psoas muscle, the athlete sits in a chair with feet flat on the floor and tries to hold one knee at belly-button level for set period of time. If he or she cannot do so, it’s assumed the psoas needs to be strengthened. Another popular test involves manually testing hip flexion while the athlete lays on a table.
While these tests may have their place in the evaluation process, it’s important to remember they have little direct transfer to athletic movement. First, the body reacts differently when gravity is involved. Second, during the gait cycle flexion usually occurs at one hip while extension occurs at the other. Thus, a high level of core stability is required to allow opposing hips to actually complement each other.
Here’s another aspect to consider: If there’s no consensus about the relative importance of the psoas and gluteus medius, neither is likely the sole solution for increasing lower-body performance. Focusing on either the psoas or the gluteus medius ignores the relationship in movement between the two and their relationship to the rest of the kinetic chain.
Single-leg exercises are also common in many popular injury-prevention programs. A common protocol is to stick the landing from a vertical drop or horizontal displacement exercise and hold the position for 10 to 20 seconds. While this improves joint stability, increases muscle fiber recruitment, and raises power, another important component still needs to be addressed.
On the playing field, athletes land and change direction in less than one second. This means that the body must effectively absorb force and be completely stable for a brief moment in order to optimally transfer application of force. Adhering to the principle of specificity, drills that require athletes to execute and hold movement patterns should have a time restriction of one second or less in coming to a complete stop.
Additional body parts may also be used as drivers during single-leg landing training. For example, if an athlete keeps both hands on his or her hips during a leap, you can evaluate the ability of the core to help decelerate motion in a single leg without further compensation from the arms.
Evaluation
The primary goal of an athletic performance evaluation is to identify strengths and weaknesses in movement patterns. The following battery of tests can be used to gain an inside look at movement habits and how they positively or negatively affect overall athletic performance. The results can then be used to help take the guesswork out of designing effective training or rehabilitation programs for the lower body.
Functional Movement Screen: Athletes have long been evaluated through speed, agility, and quickness tests as well as sport-specific skill tests. All are necessary to evaluate and understand potential areas for improvement. However, another fundamental parameter of athleticism is functional movement. This is not performance-based and does not depend on skill or strength, but rather on the athlete’s ability to complete basic movement patterns.
Five of the seven tests used in the Functional Movement Screen relate directly to the lower body: overhead squat, lunge, hurdle step, active straight-leg raise, and rotary stability. Limitations revealed by the Functional Movement Screen can interfere with athletic performance and strength and conditioning programs. They should be addressed before progressing to more sport-specific work. If these limitations are left uncorrected, athletes may adapt their movements to compensate, thus robbing them of movement efficiency, hurting their technique, and increasing the risk of injury.
Hop & Stop: The hop and stop test, originally created by Paul Juris, PhD, is designed to evaluate force production and force absorption of the lower extremities. The test takes only a few minutes to administer and the results quantify single-leg force production and absorption while also identifying asymmetry between the right and left legs.
The first part of the test evaluates force production and is measured by a hop. Starting on one leg, the athlete places the toe of the leg being measured at a start line. In a tall single-leg stance with hands on hips, the athlete raises the knee of the non-test leg to belly button height. The athlete then hops for maximal distance, landing on the same leg. The distance from the start line to where the toe of the landing foot hits the ground is measured. Three attempts for each leg are recorded.
The second part of the test evaluates force absorption as measured by a leap, which entails taking off from one leg and landing on the opposite leg. The starting position is the same as the hop and distance is measured from the start line to the toe of the landing foot.
The athlete must perform three successful leaps, which includes coming to a stop in less than a second upon ground contact, within five attempts. If more than five attempts are needed, the athlete should take a three-minute rest before trying again.
To pass the hop test, the athlete must hop 89 percent or more of his or her height. A score of less than 89 percent indicates that the athlete needs to work on force production for that leg. A normative value for the leap score is 109 percent of height, and scores lower than this indicate a need to develop force absorption for the landing leg.
Symmetry scores are determined in each category by comparing the results for the right and left legs. Asymmetry reflects possible skill and motor control differences between the legs and is separate from mobility or stability differences.
Ideally, there would be no asymmetry, but sport skills with higher levels of technical difficulty on one side than the other often make asymmetry inevitable. Recent studies show that asymmetry greater than 10 percent increases the risk of injury two and a half times. We take it a step further and aim for a variance of five percent or less.
Foot and Arch: Since the way the foot makes contact with the ground can reduce force by up to 20 percent, we also have to look closely at the foot and arch. Shoes are used to improve traction and protect feet from stress, but can also hide pronation problems that hinder lower-body performance.
Fortunately, overpronation, which indicates a lack of full dorsiflexion, can be easily seen in a deep squat when an athlete is viewed barefoot from the front and side. At the bottom of a deep squat, you will see the foot spin outward, the knee drop inside the foot, and the arch flatten completely.
Cue athletes to hold their knees outside their feet and watch them squat again. If they can perform the squat in this manner and the arch does not collapse, then they have moderate problems with pronation, which can limit their athletic effectiveness. This can be corrected through targeted work or an off-the-shelf orthotic.
If they cannot complete a deep squat or hold their knee on the outside of their foot through a deep squat, they probably need to see a physical therapist for a more thorough evaluation and, perhaps, customized orthotics. However, orthotics alone rarely improve the squat because they do not address hip mobility and core stability. Developing a proper squat pattern should be a primary focus so that the orthotics can work.
Evaluating lower-body movement patterns while the athlete is barefoot allows you to visually understand how the foot feeds the rest of the leg during ground contact and propulsion. As long as there are no abnormal foot issues, performing lower-body exercises while barefoot will aid in producing proper ground contact and heighten proprioceptive awareness of the lower extremities and trunk.
A barefoot warmup progression might include the following:
- 2-3 minutes of jogging
- Dynamic calf stretch
- Balance work
- Three-position calf stretch (toe in, toe neutral, and toe out)
- Single-leg jump rope (with and without pausing)
- Multi-directional skip
- Light agility work
Designing a Program
Once evaluation is complete you can design a program that will address the athlete’s needs. You can choose exercises to increase force production, force absorption, or core stability. (See “Training Menu”.) These exercises will also help develop joint stability, balance, and coordination of the neuromuscular system in preparation for higher levels of training intensity.
Adjustments can be made to amplitude, speed, load, time, body part restriction, and planes of movement.
A good rule to follow when incorporating evaluation feedback is to always address the negative before adding a positive. If stiffness is present, the body has to deal with a limited range of motion. The brain starts to write new motor programs to accommodate the many restrictions that have developed over time. When significant limitations are found, design a workout program based around gaining mobility before implementing stabilizing strategies.
For example, let’s say an athlete has the following results:
- Meets force production criteria on both legs (hop and stop test).
- Cannot decelerate well on the right leg compared to the left (hop and stop test).
- Scores a two in the FMS overhead squat test and displays a limited amount of dorsiflexion due to a sprained right ankle two years ago, but is presently healthy.
Before going into single-leg landing exercises to improve deceleration, we need to address the mobility issues in the right ankle. Even if the athlete improves eccentric strength in the right leg, high-intensity cutting maneuvers to the left could still present a problem. Lack of optimal dorsiflexion may also result in potential injury in the lower-extremity kinetic chain.
The “think globally, act locally” philosophy extends all the way to the core. The energy-storing ability of any plyometric action is dependent on the muscle having one stable attachment point and one mobile attachment point. In the lower body, the stable attachment point is the pelvis and lumbar segment, which work together to stabilize the core. Since the mobility of one segment is always dependent on the stability of another segment, many athletes can improve their plyometric reactions, consistency, and endurance by becoming more stable through the core and providing a more consistent and efficient attachment point.
The targeting of specific muscles certainly has a place in lower-body development, but any gains can be hampered by deficiencies elsewhere that go unaddressed. Once any deficiencies revealed by the global view have been corrected, more concentrated and localized lower-body work can realize its full potential and produce the greatest gains possible.
Case Study
The following is an example of test results from a professional athlete, along with a suggested interpretation of the results.
Background:
The athlete suffered a left hip fracture one year prior to testing. History also includes repeated right ankle sprains and occasional low back pain. There is no present pain, and the athlete is cleared to play.
Testing Results:
FMS Overhead Squat: 2 Displayed lack of mobility in the right ankle/right hip/thoracic spine.
FMS Hurdle Step: 1 for right, 2 for left. Displayed inability to balance on left leg, thus could not complete the movement. External rotation of right leg during left leg stance along with extreme lateral trunk flexion to the right side further indicates instability and lack of mobility in the left hip and core.
FMS Lunge: 2 for both right and left leg. Displayed a mobility deficiency in the right lower leg and a stability issue during left leg stance.
FMS Straight-Leg Raise: 2 for both right and left leg. Adequate hamstring flexibility but further displayed hip mobility issues.
Hop & Step:
- Hop
% Left: 87
% Right: 81
Symmetry: 8
Leap
% Onto left: 120
% Onto right: 106
Symmetry: 14
The FMS score showed there is a lack of stability in the left hip and a lack of mobility in the right ankle. In the Hop & Stop, there was a lack of adequate force production in the right leg along with a symmetry score greater than five. The leap score onto the right leg indicates a need for force absorption work. The leap symmetry score was well above five and is therefore an area of serious concern. Foot and arch evaluation was normal.
Training Suggestions:
Week 1:
- Implement mobility development strategies for the right ankle/hip/thoracic spine, stability strategies for the left hip and core, and begin deep squat progression routine.
- Teach core stability exercises.
- Include single-leg squat appropriate exercises for both legs with a higher weekly volume on the right leg.
Week 2:
- Add lunge and return series and alternate legs (force absorption), have right leg step on mini-slant board to further help turn on calf muscle.
- Add advanced core exercises as right leg mobility increases and left hip stability increases.
- Begin single-leg drop and stop progression on the right leg.
Week 3:
- Include multi-directional lunge and reach at knee level with a higher weekly volume on the right leg.
- Advance to hop and stop progression on both legs.
Week 4: Retest
Sidebar: Training Menu: The following is a list of commonly deficient areas and exercises that can be used to correct them.
Force Absorption
- Drop Squat/Lunge
- Fall & Stop Lunge
- Hop & Stop
Force Production
- Single-Leg Squat
- Walking Lunge
- Step Up
Core Stability
- Chop & Lift Patterns
- RNT Single-Leg Step Up
