Miniband Side Plank Clamshell
A side plank on your forearm with your knees bent and a mini band just above them. The top knee opens towards the ceiling and closes again — a side plank and a clamshell in one movement.
Two things are happening at once here. One is the clamshell — the opening movement, like a shell hinging open and shut. The other is lifting your hips off the floor and holding them there.
That makes the side of your hip and your trunk work together: your hips stay up and quiet while the knee opens. The mini band gives the movement something to press against, so you can feel where the work is. A band and a patch of floor is all it takes — which means it travels.
Starting position
Lie on your side with your elbow directly under your shoulder, knees bent and your shins angled back behind you. The mini band sits just above your knees. Lift your hips off the floor until your body forms a straight line from your shoulder through your hip to your knees. From there the top knee opens against the band towards the ceiling and lowers back under control — the bottom knee stays on the floor throughout.
The three cues
- Hips stacked, one directly above the other — picture a water bottle balanced on your top hip that mustn't tip
- The knee opens straight up towards the ceiling, not forward towards your chest
- The bottom knee stays glued to the floor
Common faults
| Fault | How to fix it |
|---|---|
| The thigh drifts forward instead of opening upwards | Picture a laser pointer strapped to your kneecap, pointing straight up at the ceiling. Keep the knee on that line and the glutes do the work. If it helps: less band tension, or no band for a while. |
| Your top hip rolls back towards the floor behind you | Picture that water bottle on your top hip staying upright. Keep the pelvis quiet and the work stays on the side of the hip. |
| The bottom knee lifts off the floor | That knee anchors the whole position. If it lifts, you end up shifting your weight around the position instead of loading the side of the hip. |
| The shoulder rides up towards your ear | Set the shoulder blade down and away from the ear before the hips come up. That gives the shoulder something solid to sit on. |
| The leg moves before the trunk is braced | Stack your ribcage over your pelvis and brace before the knee opens — don't let your waist sag towards the floor. Stability first, then movement. |
Variations
| Variation | When to use it |
|---|---|
| Without the band | Find the movement before you add resistance. Also the right call while the knee still drifts forward under band tension. |
| With a mini band above the knees | What we do in the studio. The band gives your knee something to press against so you can feel where the movement is coming from. |
| Long leg instead of a bent knee | The top leg stays straight and lifts towards the ceiling. A longer lever, and more work for the side of the hip. |
| Full side plank on your feet | Take the support on your feet rather than your bottom knee, and lift the top leg. The strongest version of this family for the side of the hip. |
Reps and load
The position sets the limit, not the rep count. The moment the hip drops or the knee drifts forward, the set is over.
Which muscles do the work
| Muscle | Role | What it does here |
|---|---|---|
| Glute med M. gluteus medius | Prime mover | Opens the top knee — but works hardest in the bottom, supporting leg |
| Quadratus lumborum M. quadratus lumborum | Prime mover | The lateral stabiliser beside the spine; keeps the hip up |
| Glute min M. gluteus minimus | Synergist | Works alongside glute med — it sits underneath and can't be recorded separately |
| Obliques Mm. obliqui abdominis | Synergist | Keep the trunk from rotating as the leg moves |
| TFL M. tensor fasciae latae | Synergist | Always involved; the band raises this one's activation — not the glutes' |
| Abs M. rectus abdominis | Stabiliser | Keeps ribcage and pelvis connected so the trunk doesn't collapse |
| Delts M. deltoideus | Stabiliser | Support your bodyweight through the forearm |
| Serratus anterior M. serratus anterior | Stabiliser | Keeps the shoulder blade on the ribcage so the shoulder stays down |
The top knee makes the visible movement, but the bottom, supporting leg holds the hip up and carries the larger share. The tensor fasciae latae is always involved. That's what the knee cue is for: point the knee at the ceiling and the glutes lead.
Ways to do it — on video
The equipment changes, the movement pattern stays the same. What you learn on the cable applies to the band just as much — only the resistance differs.
With a mini bandStandard
The studio standard. Side plank on the forearm, knees bent, band just above the knees, the top knee opening against the resistance and coming back under control.
Long leg
Instead of the knee opening, the top leg stays straight and lifts towards the ceiling. A longer lever, and more work for the side of the hip.
Seeing it done right is not the same as doing it right
Video, cues and variations take you a long way. What they cannot give you is an outside eye at the moment the movement isn't quite there yet. That is what training with me is for — in the studio or in a workshop.
See the workshopsNew exercise pages are added all the time — the newsletter keeps you posted.
Sources
Youdas JW, et al. (2014). Sports Health 6(5):416–421. DOI: 10.1177/1941738114539266 — The only study to record this exact version — forearm support, knees bent, top knee opening. Glute med worked considerably harder in the supporting leg than in the moving one. 25 people, surface EMG, no band. (Evidence type: EMG)
Selkowitz DM, Beneck GJ, Powers CM. (2013). J Orthop Sports Phys Ther 43(2):54–64. DOI: 10.2519/jospt.2013.4116 — Fine-wire electrodes rather than surface EMG, 20 people: across eleven exercises the clam had the best glute-to-TFL ratio. Recorded lying on the side, not in a side-plank position. (Evidence type: EMG)
Bishop BN, et al. (2018). Int J Sports Phys Ther 13(4):668–675. DOI: 10.26603/ijspt20180668 — The only direct comparison of the banded and unbanded version in the same people: the tensor fasciae latae rose significantly, the glutes were unchanged. Eleven people, lying on the side. (Evidence type: EMG)
Distefano LJ, et al. (2009). J Orthop Sports Phys Ther 39(7):532–540. DOI: 10.2519/jospt.2009.2796 — Side-lying straight-leg abduction reached 81 per cent of maximum, the clam 40 and 38 per cent depending on hip angle — the basis for the long-leg variation. 21 people. No side plank was among the exercises here, though it is often cited online as though there was. (Evidence type: EMG)
McGill S, Juker D, Kropf P. (1996). Clin Biomech 11(3):170–172. DOI: 10.1016/0268-0033(95)00056-9 — Fine-wire EMG recorded directly from quadratus lumborum: in the side-bridge position it reached 54 per cent of its maximum, more than in any other task tested. Only four people were measured, so the direction is trustworthy but the exact figure isn't. (Evidence type: EMG)
Boren K, et al. (2011). Int J Sports Phys Ther 6(3):206–223. Volltext (PMC3201064) — Of 18 exercises compared, the side plank with abduction produced the highest glute med demand: 103 per cent of maximum for the bottom leg and 89 per cent for the top. Worth knowing for context: there the support is on the elbow and feet — the harder step on this page, not the version on the knee. (Evidence type: EMG)
A note on context: EMG studies show which muscles an exercise recruits — that is a good reason to pick it, but it does not replace adjusting things to the person in front of you. See a doctor for persistent or severe pain.