Friday, May 11, 2007

Hip Extensions & Healthy Hamstrings

Hip Extensions & Healthy Hamstrings
From Functional Training for Sports, M. Boyle, Human Kinetics, 2004. pp 73-84
The muscles that extend the hip, primarily the gluteus maximus and hamstring group, are often neglected, even in many functional training programs. Programs frequently place excessive emphasis on the knee extensors and neglect the hip extensors. Even more disturbing, the muscles that extend the hip, especially the hamstrings, are often mistakenly trained as knee flexors. In non functional strength programs, many muscle groups are still trained according to outdated understandings of their functions.

Although some anatomy texts describe the hamstring group as knee flexors, science now tells us that the hamstrings are powerful hip extensors and stabilizers of the knee. Hamstrings are only knee flexors in nonfunctional settings. In running jumping or skating, the function of the hamstrings and glutes is not to flex the knee but to extend the hip. As a result, lying or standing leg curls are generally a waste of time for athletes. Leg curl exercises the muscles in a pattern that is never used in sport. Training the muscles in non functional patterns may explain the frequent recurrence of hamstring strain in athletes who rehabilitate with exercises such as leg curls or isokinetics.

Hip Extension Exercises
There are two distinct types of hip extension movements; straight leg hip extensions and bent leg hip extensions. It is critical to use exercises from both categories to properly train the posterior chain muscles (glutes and hamstrings)…

…It is important to note that knee flexion exercises such as squats and variations affect the glutes and hamstrings only as they relate to knee extensions and hip extensions in achieving a neutral standing position. To more fully involve the glutes and the hamstrings the movements must be centered on the hip and not the knee…

Level 1 Exercises
The hyperextension is possibly the worst named exercise in the functional training toolbox. Hyperextensions may be referred to as back extensions or back raises, but whatever the name, should be included in every beginning strength program. (This exercise is also called Glut-Ham Raises which more accurately describes the exercise – Ed). The hyperextension is a great basic exercise that teaches the athlete to use the glutes and hamstrings as hip extensors. Despite the name the emphasis should not be on hyperextending the lumber spine but rather on using the glutes and hamstrings as hip extensors. The exercise has three major benefits.

It strengthens the posterior aspect of the trunk (spinal erectors); it works the low back extensors in primarily an isometric, rather than concentric or eccentric, fashion. The spinal erectors (low back muscles) are critical for maintaining proper position in all standing exercises.
It strengthens the glutes and hamstrings as hip extensors. Many people view the hyperextension as a lower back exercise but it is actually an excellent exercise for the upper hamstrings and glutes.
It promotes flexibility in the low back and hamstrings. The actions of lowering and raising the weight of the torso stretch the hamstring group.

Level 2 Exercises
Modified Straight Leg Deadlift
The modified Straight Leg Deadlift (SLDL) ranks with the squat among frequently maligned, misunderstood and poorly executed lifts. The squat and deadlift and their variations are often called unsafe and dangerous. In truth, these lifts are extremely safe and beneficial when performed correctly with an appropriate load. However the squat and the SLDL can be dangerous when performed improperly or with too heavy a weight. The modified SLDL is performed with the legs slightly bent and the back arched. The SLDL, like the hyperextension is an isometric exercise for the spinal erectors (lower back muscles) and a concentric exercise for the hamstrings and glutes. It works the lower back musculature similarly to the squat.

Please not that this is an extremely difficult lift to teach and should be learned with a dowel or weight bar prior to loading.
Technique Points
For dumbbell SLDLs, the dumbbells are held with the palms in towards the thighs (neutral grip), and the hands should move down the outside of the thigh to the shin.
For a straight bar use a clean grip. Arms are straight. Wrists are curled under to encourage elbow extension.
Feet should be approximately hip-width apart. Knees are slightly bent.
Keep the back arched, the shoulder blades retracted and the chest up.
While maintaining your back position, slide the bar down your thighs until you reach the end of your hamstring range of motion.

The keys to the SLDL are bending from the hip and pushing the butt back while maintaining and arched back. Concentrate on pushing the hips and butt back, not on leaning forward. Athletes should start with the weight on the balls of the feet and, as they descend, shift their weight to the heels by pushing the butt back. Maintaining back position is important. Athletes must maintain at least a flat back. If they begin to flex the spine, they have reached the end of the active range of motion of the hamstrings. Remember that this is an isometric exercise for the spinal erectors and a concentric exercise for the glutes and hamstrings. Movement should come from the hip, not from the lumbar spine.

Perform for multiple sets of 5-12 depending on the level of training. Generally no fewer than 5 reps should be done, as a precaution against back injury (due to high loads)

Level 3 Exercises
Two-Leg Stability Ball Hip Extension

A 65cm stability ball is used. The stability ball hip extension uses the hamstrings and glutes as hip extensors. It is extremely important that the movement comes from the hip and not from the lumbar spine.

Technique Points
Place the soles of the feet on the stability ball with hips and knees flexed to 90 degrees.
Place the arms at the sides.
Press the feet down onto the ball with the glutes and hamstrings
Raise the hips up until there is a straight line from the knees to the shoulders.
Extend the hips, not the lumbar spine. Attempt to draw in the abdominals to stabilize the back.
Think hip extension, not lumbar extension.

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