Side plank
A plank on one side, resisting the hips dropping — and the only common trunk movement that loads the side.
- Pattern
- Anti-lateral flexion
- Equipment
- Nothing needed
- Space
- Floor space
- Difficulty
- Developing
- Load
- Leverage
- Side
- One side at a time
What it is
Lie on one side, forearm on the floor with the elbow under your shoulder, legs stacked. Lift your hips so your body is a straight line from head to feet, supported on your forearm and the side of your lower foot. Hold.
Bending the lower knee and resting the shin on the floor makes it substantially easier and is a perfectly good version. So is stacking the feet in a small stagger rather than exactly on top of one another.
What it demands
Resisting sideways bending. Gravity is trying to fold you towards the floor at the hip, and the muscles on the upper side are stopping it. That is the obliques and quadratus lumborum, and it is a demand nothing in a front plank produces.
Hip abduction endurance on the bottom side — gluteus medius and gluteus minimus holding the pelvis up.
Shoulder stability on the supporting side, which is often the part that complains first.
What usually goes wrong
The hips drop. The line breaks and the exercise is over. As with the front plank, this is the honest end of the set.
Rolling forward or backward. The chest should face directly sideways. Rotating towards the floor makes it easier and turns it into something else.
The supporting shoulder shrugging up. Press the floor away slightly so the shoulder sits down rather than jamming towards the ear.
Skipping one side. This is a single-sided movement and the two sides are commonly unequal. Doing both, and matching the weaker side, is the point.
Where it sits
The side plank fills a genuine gap: the front plank and most trunk exercises work front-to-back, and this is the one that loads sideways.
It is also the trunk movement that most clearly doubles as hip work, because holding the pelvis up on one side is exactly the job the gluteal muscles do in single-leg stance — the same demand as the single-leg glute bridge, from a different angle.