The hanging leg raise (HLR) is an advanced bodyweight movement requiring significant strength and coordination. This exercise involves suspending the body from a bar and raising the legs against gravity. Successfully executing the HLR requires a complex interplay between the muscles that initiate the leg lift and the deep muscles responsible for spinal stability and pelvic control. Understanding the specific muscle groups that contribute to this movement is key to maximizing its effectiveness.
The Primary Movers: Targeting the Hip Flexors
The initial action of lifting the legs upward is powered by the hip flexor group, the primary engine for this phase. Hip flexion decreases the angle between the femur and the pelvis. The most powerful muscle driving this action is the Iliopsoas, which includes the Psoas major and the Iliacus muscles. Originating in the lumbar spine and pelvis, the Iliopsoas pulls the legs toward the trunk. If the movement stops when the legs are parallel to the floor, the exercise primarily targets these hip flexors.
The Rectus Femoris, one of the quadriceps muscles, also assists in hip flexion because it crosses the hip joint. However, focusing only on hip flexion limits the exercise’s full benefit. Without proper core engagement, the strong pull of the Iliopsoas can cause an anterior pelvic tilt, stressing the lumbar spine. To become a true abdominal exercise, the HLR must incorporate the secondary action of pelvic rotation.
Engaging the Core: Pelvic Tilt and Abdominal Contraction
To transition the HLR into a comprehensive core movement, a secondary action must occur: the posterior pelvic tilt and subsequent spinal flexion. At this point, the abdominal muscles take over the primary role, working against the resistance of the legs. The Rectus Abdominis, the long muscle running vertically along the abdomen, is responsible for this curling action.
It functions by pulling the ribs and sternum closer to the pubic area. In the HLR, this means the muscle contracts to curl the pelvis up and under, flexing the lumbar spine. This pelvic tuck differentiates an effective HLR from a simple, hip-dominant leg lift. The deep core’s role is to pull the pelvis, which acts as the attachment point for the heavy leg lever, up toward the rib cage.
The Obliques, both internal and external, assist the Rectus Abdominis during this final phase of spinal flexion. These side abdominal muscles also prevent the body from swinging laterally during the dynamic movement. Actively contracting the obliques and the Rectus Abdominis to perform the posterior tilt maximizes the recruitment of the entire abdominal wall.
Stabilization and Isometric Strength
Before dynamic movement begins, isometric strength is needed to maintain the hang and control the body’s position. The ability to hang relies primarily on the forearm muscles. The forearm flexors and extensors work intensely to maintain a secure grip, which is often a limiting factor in the exercise.
The upper body must stabilize the shoulder girdle to prevent unwanted swinging and provide a rigid anchor point. The Latissimus Dorsi (lats) are powerful back muscles that work isometrically to depress the shoulders. This downward pull keeps the shoulder joint secure and prevents the body from passively hanging with shrugged shoulders.
The deep core stabilizers, including the Transverse Abdominis, also engage isometrically throughout the movement. This muscle acts like an internal corset, wrapping around the midsection to maintain torso rigidity and protect the spine. The combined isometric contraction of the grip, shoulder depressors, and deep core allows the exerciser to maintain a controlled, non-swinging vertical position.