HANGING KNEE/LEG RAISE
EXECUTION
- Step up on a low stool or jump to grasp a high bar so that your body hangs freely without your feet touching the floor.
- Grasp the bar with a pronated, palms away grip. Hang with your arms fully extended and with a slight arch in your lower back.
- Inhale and hold your breath as you bend your legs to a 90? or less angle in the knees and raise the thighs as high as possible.
- For greater effectiveness, raise the knees up above the thigh level position with a momentary hold in the up position.
- Exhale and relax as you return the legs to the initial position under control. Pause momentarily and then repeat.
- When the bent leg version becomes easy, do the exercise with straighter legs.
- Be sure to start from a stationary position and lift your legs up as strongly as possible with your hip flexor and abdominal muscles.
- Gradually work up to using straight legs and touching the bar with the feet.
TRAINING TIPS
- When first attempting this exercise begin with the bent knee variant.
- For the strongest muscle contraction through the greatest range of motion, be sure to raise the legs as high as possible, well above the thigh-level position.
- The higher the legs are raised, the greater the abdominal muscle involvement. The reason for this is that the first part of raising the legs upward is made possible by the concentric contraction of the hip flexors while the abdominals are isometrically contracted. The abdominals begin to contract concentrically (shorten) when the thighs reach approximately a 30-45? angle to the vertical. Thus, the higher the legs go, the greater the rotation of the pelvis and the greater the involvement of the abdominal muscles.
- Although involvement of the hip flexors in abdominal exercises has been negatively criticized, this involvement should not be feared. The abdominal and hip flexor muscles have a close working relationship and are always involved together. You cannot eliminate one or the other contraction in movements of the legs and pelvic girdle.
- Do not swing the body to help raise the legs. The body should be still when you begin raising the legs. Arching the lower back and then vigorously bringing the legs up is acceptable as it pre-stretches the muscles to ensure a stronger contraction.
- When hanging from the hands, you get a beneficial stretch of the entire spine. This in turn, can help maintain or improve your posture especially if you have a tendency to slouch or have a job where you are constantly bent over as in typing or working on a computer.
- Because your legs form a long lever and the shoes that you wear are typically fairly heavy, additional resistance is not usually needed. The long leg lever with weighted feet increases the difficulty of the exercise greatly.
- The tighter your hamstring muscles, the sooner the abdominal muscles come into play to rotate the pelvis. If you have good hamstring flexibility, you can probably raise the legs somewhat higher before the abdominals begin to shorten.
MAJOR MUSCLES INVOLVED
The major muscles involved in raising the legs (hip flexion) are the psoas and iliacus, collectively known as the iliopsoas, the rectus femoris and the pectineus. The psoas lies deep in the abdomen and the iliacus lies to the side of the psoas on the inner surface of the ilium, the side bone of the hip. The rectus femoris is a long muscle that runs straight down the front of the thigh and is one of the major muscles of the quadriceps femoris muscle group. The pectineus is a short thick muscle located close to the groin and is covered somewhat by the sartorius and rectus femoris muscles. The primary abdominal muscles involved are the rectus abdominis, a long slender muscle that extends vertically from the pubic bone to the sternum and the internal and external obliques which cover the front sides of the abdomen from the rectus abdominis to the latissimus dorsi. The fibers of the internal and external oblique run at 90? to one another in the upper portion of the abdomen. The side-angled muscle fibers can be seen when the muscles are well developed and you have little fat in this area. They can greatly complement the “six pack” effect.
MUSCLE/JOINT ACTIONS
The hip joint muscles come into play initially to perform hip joint flexion in which the legs are in raised while the pelvis is stabilized by isometric contraction of the abdominals. As hip flexion reaches it maximum range of motion (approximately 30-45? from the vertical position) the legs and pelvic girdle maintain their position via isometric contraction of the hip flexors. The abdominal muscles, initially the lower portion, then come into play to rotate the pelvis backward to continue raising the legs. The leg-hip joint angle remains the same as the pelvis is rotated backward (the top of the pelvis moves backward). The higher the legs are raised the greater is the hip rotation and corresponding involvement of the middle and upper portions of the abdominals.
SPORTS USES
In bodybuilding, strengthening the hip flexor muscles is important for maintaining balance with the hip joint extensor (gluteus maximus and hamstring) muscle development and, to a limited extent, the muscles of the lower back. The abdominal strengthening plays a role in spinal stability and in various sports performances. In the straight leg variant, you get involvement of both the lower and upper portions to ensure maximum muscle shortening to produce the greatest tension, and, as a result, the greatest amount of strength and definition. In sports, hip and spinal flexion (backward rotation of the pelvis) are extremely important for raising the legs high in front of the body. This is seen in raising the legs in dance, ballet and chorus lines, kicking as seen in karate and soccer, in running when driving the thigh forward in the push off, and when taking a long step to reach a ball or other object as in tennis, field hockey and lacrosse. Leg raises are important in sports such as gymnastics, especially on the bars and in free exercise, rhythmic gymnastics, pole vaulting, hurdling, kick boxing and others. Development of the muscles involved reduces risk of injury to the lower back since these muscles help to stabilize the pelvis, which in turn helps maintain proper alignment of the spine.