Side Plank Progression:

By Brent Brookbush MS, PES, CES, CSCS, ACSM H/FS

Function: The side plank is an excellent exercise for increasing frontal plane stabilization of the core. The side plank is often used to strengthen the obliques, but the obliques are not the primary lateral flexor of the spine, nor do they cross the hip (prime movers: Spine - quadratus lumborum, Hip - gluteus medius). However, when this exercise is performed well, it can be an excellent way to strengthen the lateral core sub-system, and integrate a weak gluteus medius into core activity.

Side Plank Kinesiology:

Isometric Hip Abduction

• Agonists - Gluteus Medius
• Synergists – Gluteus Maximus (superior fibers), Gluteus Minimus, Tensor Fascia Latae, Sartorius,
• Antagonists – Adductor Magnus, Pectineus, Adductor Brevis, Adductor Longus, Gracilis, Gluteus Maximus (inferior fibers) Quadratus Femoris
• Neutralizers – The abductors of the thigh also contribute to rotation. A careful balance of strength and flexibility between internal and external rotators ensures optimal muscular synergies.
• Stabilizers – Psoas, rectus femoris, biceps femoris, semitendinosus, semimembranosus, vastus lateralis, piriformis, deep rotators of hip (obturator internus, gemellus superior, inferior gemellus, quadratus femoris, obturator externus) rectus abdominis, obliques, quadratus lumborum, erector spinae, Intrinsic Stabilization Subsystem (transverse abdominis, diaphragm, levator ani, coccygeus, multifidus, rotatores, interspinales, intertransversarii)

Isometric Lateral Flexion (of spine):

• Agonists - Quadratus Lumborum
• Synergists – Ipsilateral External Oblique and Internal Oblique, Rectus Abdominis, Ipsilateral Latissimus Dorsi , Ipsilateral Erector Spinae (Multifidi & Intertransversarii -including these muscles as movers of the spine is debatable. There relative size, length, and proximity to the axis of rotation gives these muscle poor leverage for gross movement. However, this position is advantageous for proprioception and segmental stabilization)
• Antagonists – Contralateral Quadratus Lumborum, external and internal obliques
• Neutralizers – Erector Spinae neutralize flexion force created by obliques, intrinsic stabilization system creates posterior shear force on lumbar spine to neutralize lumbar extension.
• Stabilizers – Psoas, Intrinsic Stabilization Subsystem (Transverse Abdominis, Diaphragm, Pelvic Floor (levator ani, coccygeus), Multifidus, Rotatores, Interspinales, Intertransversarii

Subsystem Stressed:

• Intrinsic Stabilization Sub-system - Transverse Abdominis, Diaphragm, Pelvic Floor (levator ani, coccygeus), Multifidus, Rotatores, Interspinales, Intertransversarii
• Lateral Stabilization Sub-subsystem – Gluteus Medius, Quadratus Lumborum, Adductors

Side Plank: Functional training is multi-planer

Side Plank Progression:

1. Side Plank on knees
2. Side Plank on knees and with contralateral leg abducted
3. Side Plank on knees and with contralateral leg dynamically abducts with slight extension and external rotation.
4. Side Plank on knees and arm on unstable surface (Airex pad, PB disk, Bosu)
5. Side Plank on knees and arm on unstable surface with contralateral leg abducted
6. Side Plank on knees and arm on unstable surface with contralateral leg actively abducts with slight extension and external rotation
7. Side Plank on feet
8. Side Plank on feet with contralateral leg abducted
9. Side Plank on feet with contralateral leg dynamically abducts with slight extension and external rotation
10. Side Plank on feet and arm on unstable surface (Airex, PB disk, Bosu)
11. Side Plank on feet and arm on unstable surface with contralateral leg abducted
12. Side Plank on feet and arm on unstable surface with contralateral leg actively abducts and extends

Notes on form:

The hips are often the first misstep in form. The tendency is to slip into an anterior pelvic tilt and roll forward. This allows a synergistically dominant TFL to compensate for gluteus medius weakness. The hip should be forward, with tail bone tucked and glutes tight. Cueing glute contraction by driving the hips forward, and pressing the bottom knee or foot into the ground should improve from. If optimal lumbo-pelvic-hip complex alignment cannot be maintained, select the appropriate regression of the exercise.

The shoulder girdle is often the second misstep. It should be - as if the forearm is being driven into the floor. This will ensure scapular abduction and serratus anterior activation, which in turn will stabilize the shoulder girdle.

Last keep the head in a neutral position. Although this may feel awkward at first, allowing the head and neck to laterally flex reinforces poor mechanics that could place scapular stabilizers at less than optimal length. Repetition could lead to trigger points, hypertonicity and pain.

© 2011 Brent Brookbush

Questions, comments, and criticisms are welcomed and encouraged – Brent@b2cfitness.com