EXECUTION
- Lie face down on a leg curl bench, preferably an angled bench
- Position yourself so that your knees are beyond the far edge of the bench and the resistance rollers adjusted so that they rest against the back of the ankle (lower shin)
- Grasp the handgrips or sides of the bench, if grips are not available
- When ready, inhale and hold your breath as you flex the knees to raise the resistance rollers (feet)
- In the ending or top position, your shins should be vertical or slightly closer to the thighs
- Hold for 1-2 seconds and then exhale as you return to the original position under control
- Do the movement at a moderate rate of speed
- Keep your toes in line with the shins (not angled outward or inward) throughout the up and down movements
Workout Tips
- The angled bench is preferred to a flat bench as it places the hips in a more favorable position, which places the hamstrings on stretch. With a flat bench, you must hyperextend the spine in order to raise the hips to place the hamstrings on stretch. Doing this can create problems in the lumbar spine.
- Be sure to execute the movement at a moderate rate of speed. If you do the movement too slowly when using heavy weights, the forces involved in stabilizing the knee become very high and may over-stress the joint. With heavy weights, a powerful explosive contraction may be needed to get the movement started.
- Be sure to return to the full straight leg position before repeating. Stopping short of full range will create muscle tightness, preventing you from being able to fully extend the legs when doing the leg extension exercise and when doing sports activities.
- Strength of the inner and outer hamstrings must be balanced in order to provide equal lateral stability to the knee joint and to prevent excessive outward or inward rotation of the foot.
- If your outer hamstrings (the biceps femoris) is overly powerful, you will turn your foot outward as you do the exercise and as you walk or run. To balance it’s strength, you should do the leg curl exercise with your toes pointed inward.
- If your inner hamstrings (the semimembranosus and semitendinosus) are overly powerful, your feet will turn inward as you do the movement. To balance the muscular development, do the exercise with your feet pointed outward.
- To ensure knee joint safety, your knee should extend beyond the edge of the bench. If your knees are on the bench, tremendous pressure can build up under the knee caps, which can cause injury.
- If you use a flat bench, do not have someone hold the hips down to prevent them from rising. The hip raising action is a natural movement to place the hamstrings in position for a strong contraction.
- To get greater involvement of the gastrocnemius muscle, keep the feet in a dorsi flexed position, i.e., with the toes toward the shins.
- The hamstrings should not be equal to the quadriceps in relation to muscular strength. The quadriceps should always be stronger, mainly because it is a much larger muscle and must do more work. However, the stronger the hamstrings, the better the balance between these two opposing muscle groups, which in turn helps to stabilize the entire knee joint, making it less prone to injury.
Major Muscles Involved The hamstring muscle group, which is composed of the semimembranosus, semitendinosus and biceps femoris muscles, which are two-jointed muscles having an action at both the hip and knee joints. The largest is the biceps femoris which has two heads at the lower end. Both heads act in knee joint flexion and outward rotation of the shin at the knee. Since the biceps tendon crosses the outside of the knee it is known as the lateral hamstring.
The semitendinosus and the semimembranosus are long slim muscles. Their tendon of insertion is on the inner side of the knee joint and they are known as the medial hamstrings. Not only are they prime muscles for knee flexion but also inward rotation of the shin. The muscle bulk of the semitendinosus is in the upper half of the thigh while the muscle mass for the semimembranosus is lower so that the two muscles joint to form a cylindrical mass.
Assisting in knee flexion is the gastrocnemius muscle, a two-jointed muscle, which assists in knee joint flexion and is a prime mover for ankle joint extension. The gastrocnemius gives the rounded form to the calf of the leg.