The side plank is a foundational stabilization exercise targeting the trunk’s lateral muscles, which are often underdeveloped compared to the front or back of the core. This isometric movement trains the body’s ability to resist lateral flexion, preventing the torso from bending sideways. Incorporating the side plank builds a strong, balanced center that translates to better performance in daily activities and other exercises. Mastering proper form is paramount to maximizing benefits and protecting the shoulder and spine from strain.
Executing the Standard Side Plank
To begin the standard side plank, lie on one side with the legs extended straight out and the feet stacked. Place the forearm on the ground, ensuring the elbow is positioned directly beneath the shoulder joint for best leverage and to prevent stress. The body initially rests on the forearm and the side of the bottom foot.
Before lifting, engage the abdominal muscles by pulling the navel toward the spine, and gently squeeze the glutes. This pre-activation helps to set the pelvis and lumbar spine in a neutral position, avoiding an arched or rounded lower back. Press down through the forearm and the side of the bottom foot to lift the hips off the floor.
The goal upon lifting is to create a straight line from the ankles through the hips and shoulders to the head. Actively push the bottom hip upward toward the ceiling, ensuring the hips do not sag toward the floor or pike too high. Maintain a neutral neck alignment by looking straight ahead or slightly down, keeping the chin tucked in line with the spine.
Holding this position requires continuous muscle engagement to maintain alignment. Focus on slow, controlled breathing, avoiding the tendency to hold the breath. The non-supporting arm can be placed on the top hip or extended toward the ceiling for increased stability.
Muscles Targeted by the Side Plank
The side plank primarily engages the internal and external oblique muscles, which run along the sides of the abdomen and resist trunk rotation and lateral bending. These muscles work isometrically to maintain the static side-lying position against gravity. The transverse abdominis, which wraps around the torso, is also activated deep within the core to stabilize the spine.
The exercise also recruits the gluteus medius and gluteus minimus, which are hip abductors and stabilizers. These muscles maintain the stacked alignment of the pelvis and prevent the bottom hip from dropping. On the supporting side, the shoulder joint’s rotator cuff and surrounding scapular stabilizers are highly active, preventing the shoulder from collapsing and providing a stable base.
Correcting Common Form Mistakes
One frequent error is allowing the hips to sag toward the floor as fatigue sets in, which reduces the activation of the obliques and glutes. To correct this, actively drive the bottom hip up and away from the floor, imagining a string pulling the hip toward the ceiling.
Another common issue is the collapse of the supporting shoulder, where the chest caves in and the shoulder blade wings out. The correction involves pressing forcefully through the forearm and elbow, actively pushing the floor away to keep the shoulder joint stable and the chest open.
Some individuals let their hips roll forward or backward, often happening when the feet are not perfectly stacked or the glutes are not fully engaged. To fix a rolling pelvis, concentrate on keeping the hips stacked, aligning the top hip directly over the bottom hip, and squeezing the glutes to lock the lower body.
Finally, craning the neck by letting the head drop or look up can strain the cervical spine. Maintain a neutral head position, ensuring the ear, shoulder, and hip remain aligned, with the gaze directed forward or slightly toward the floor.
Scaling the Side Plank (Modifications and Advanced Options)
For those who find the full side plank too challenging, the most common modification is the bent-knee side plank. This reduces the length of the lever and provides a wider base of support. In this variation, the lower knee is bent to 90 degrees and remains in contact with the floor, forming a straight line from the shoulder to the knees. This allows focus on core and shoulder stability without the full load of the legs.
Once the standard forearm side plank can be held with perfect form for 30 to 60 seconds, several advanced options increase intensity. Progressing to a straight-arm side plank, with the hand under the shoulder, increases the lever length and demands greater shoulder stability. Dynamic variations, such as the side plank hip dip, involve lowering the hips until they nearly touch the ground and then raising them back up, adding a concentric and eccentric load to the obliques.
Another progression is the side plank with a leg raise, where the top leg is lifted a few inches off the bottom leg, significantly increasing the activation of the gluteus medius to resist rotational forces at the hip. For a greater challenge incorporating rotation, the side plank thread-the-needle variation involves reaching the top arm underneath the body and then returning to the starting position. Using external resistance, such as holding a light dumbbell, can also increase the demand on the stabilizing muscles.