Plank exercise

Original Editor - Ahmed Nasr Top Contributors - Lucinda hampton, Lilian Ashraf, Kim Jackson, Ahmed Nasr and Joao Costa

Description[edit | edit source]

The plank exercise is an isometric core exercise that involves maintaining a position similar to a push-up  for the maximum possible time.

Image 1: The Plank

Technique[edit | edit source]

Lying on the ground with the elbows in line with the shoulder and the feet shoulder width apart, Push your body up bearing the weight on  the forearms and feet, Keeping your body straight.[1]

Muscles activity [edit | edit source]

Overview of the muscles of the abdominal wall - anterior view

The plank activates the core muscles including:

The first muscle activated is the transversus abdomini which increases the spine stiffness, increasing the spine stability.[4] 

Image: Overview of the muscles of the abdominal wall - anterior view[5]

Advantages[edit | edit source]

  • Plank exercise can activate core muscles with low compressive forces (1600 to 1800N) avoiding high compressive forces on the lumbar vertebrae, which occur in back extension, trunk curls or lying prone with extended arms and legs[6]
  • During the plank exercise the aim is to try and maintain a neutral spine against the forces acting on it. Gravity poses a downward force on the elevated trunk, while the contact points on the ground (toes and forearms) counteract the downward force with an upward force, this results in the trunk wanting to “dip”. For correct form it is essential that the core muscles, especially the abdominal muscles, activate to resist the downward force and potential dipping to ensure the spine remains in neutral.[6]

Correct Technique[edit | edit source]

  • AOS Anatomy.png
    It has been demonstrated that doing isometric dorsiflexion during plank exercise causes increased activation of the abdominal muscles compared to isometric planterflexion[7]
  • Abdominal muscles are attached to adductors by a sling called anterior oblique sling. Doing unilateral isometric hip adduction results in increased activation of the abdominal muscles compared to bilateral isometric hip adduction[8]
  • !mage 3: The two Anterior Oblique Systems supporting the pelvis.
  • Attentional focus on abdominal muscles (upper or lower abdominal), during this exercise, has shown increased activation of the abdominal muscles compared to not focusing on the abdominal muscles [9]

Normative Values[edit | edit source]

Rating Time
Excellent > 6 minutes
Very Good 4-6 minutes
above average 2-4 minutes
Average 1-2 minutes
below average 30-60 seconds
poor 15-30 seconds
very poor < 15 seconds

[10]

Stable vs Unstable surface[edit | edit source]

Plank with medicine ball.jpeg

Performing the plank exercise on an unstable surfaces increases core muscles activity more than performing it on stable surface due to increasing the muscle demand.[3]

Image 4: Plank with medicine balls.

The unstable surface can be provided by dynamic cushion or suspension device.[3]

Yong-chan Do et al, study shows higher activation of the transversus abdominis with dynamic lower limb cushion more than the dynamic upper limb cushion, to maintain pelvic stability.[2]

Variations[edit | edit source]

There are many variations of the plank exercise, including;

  • Front plank
  • Front plank with hip extension: high activation of gluteus max.
  • Side plank
  • Side plank abduction : high activation of gluteus medius on the contralateral weight bearing side.[11]

Significance to physiotherapy[edit | edit source]

It is used for the prevention and rehabilitation of low back pain as a part of core training programs.[12]

Performing the plank exercise on an unstable surface can be used as a progression to increase trunk stability.[13]

It has a positive effect on injury prevention.[14]

References[edit | edit source]

  1. Schoenfeld BJ, Contreras B, Tiryaki-Sonmez G, Willardson JM, Fontana F. An electromyographic comparison of a modified version of the plank with a long lever and posterior tilt versus the traditional plank exercise. Sports biomechanics. 2014 Jul 3;13(3):296-306.
  2. 2.0 2.1 Do YC, Yoo WG. Comparison of the thicknesses of the transversus abdominis and internal abdominal obliques during plank exercises on different support surfaces. Journal of physical therapy science. 2015;27(1):169-70.
  3. 3.0 3.1 3.2 Lee J, Jeong KH, Lee H, Shin JY, Choi JL, Kang SB, Lee BH. Comparison of three different surface plank exercises on core muscle activity. Physical Therapy Rehabilitation Science. 2016;5(1):29-33.
  4. Selkow NM, Eck MR, Rivas S. Transversus abdominis activation and timing improves following core stability training: a randomized trial. International journal of sports physical therapy. 2017 Dec;12(7):1048.
  5. Overview of the muscles of the abdominal wall - anterior view image - © Kenhub https://www.kenhub.com/en/study/muscles-of-the-abdominal-wall
  6. 6.0 6.1 James W, Kendra C, Erin E, Stephanie D, Nicole L. John H. Hollman. Magnitudes of muscle activation of spine stabilizers in healthy adults during prone on elbow planking exercises with and without a fitness ball. Physiotherapy Theory and Practice.2018:34:
  7. Choi JH, Kim DE, Cynn H. Comparison of Trunk Muscle Activity Between Traditional Plank Exercise and Plank Exercise With Isometric Contraction of Ankle Muscles in Subjects With Chronic Low Back Pain. Journal of Strength and Conditioning Research.May 2019. 1064-8011
  8. Soo YK, Min HK, Eui RK, In GJ, Eun YS, Jae SO. Comparison of EMG activity on abdominal muscles during plank exercise with unilateral and bilateral additional isometric hip adduction. Journal of Electromyography and Kinesiology. 2016 :30: 9-14.
  9. Calatayud J, Casaña J, Martín F, Jakobsen MD, Andersen LL, Colado JC. Electromyographic Effect of Using Different Attentional Foci During the Front Plank Exercise. American Journal of Physical Medicine & Rehabilitation. 2019: 98(1):26-29.
  10. Top and Sports The plank fitness test Available: https://www.topendsports.com/testing/tests/plank.htm (accessed 31.1.2022)
  11. Boren K, Conrey C, Le Coguic J, Paprocki L, Voight M, Robinson TK. Electromyographic analysis of gluteus medius and gluteus maximus during rehabilitation exercises. International journal of sports physical therapy. 2011 Sep;6(3):206.
  12. Calatayud J, Casaña J, Martín F, Jakobsen MD, Colado JC, Andersen LL. Progression of core stability exercises based on the extent of muscle activity. American journal of physical medicine & rehabilitation. 2017 Oct 1;96(10):694-9.
  13. Calatayud J, Casaña J, Martín F, Jakobsen MD, Colado JC, Gargallo P, Juesas Á, Muñoz V, Andersen LL. Trunk muscle activity during different variations of the supine plank exercise. Musculoskeletal Science and Practice. 2017 Apr 1;28:54-8.
  14. Byrne JM, Bishop NS, Caines AM, Crane KA, Feaver AM, Pearcey GE. Effect of using a suspension training system on muscle activation during the performance of a front plank exercise. The Journal of Strength & Conditioning Research. 2014 Nov 1;28(11):3049-55.