My project researches the muscle groups of the lower body required to achieve a full backwards layout starting with a deep squat position. I have extracted four still images from a recorded video of two individuals performing the aforesaid motion and used two peer-reviewed articles to describe the muscle groups involved in acquiring each still motion photo. The images and citations are as follows:

  1. Description: Squat position 

The muscle groups involved in a deep knee squat include the gluteus maximus, biceps femoris, semitendinosus, rectus femoris, vastus lateralis, soleus, gastrocnemius, and tibialis anterior muscles about their associated joints during full (deep-knee) squats. (2)

  • Description: Squat with low backwards hand thrust to build momentum

The biarticular muscles functioned mainly as stabilizers of the ankle, knee, and hip joints by working eccentrically to control descent or transferring energy among the segments during ascent. (2)

  • Description: Ascent of deep squat into full backwards layout

Analyses revealed that the prime movers during ascent were the monoarticular gluteus maximus and vasti muscles (as exemplified by vastus lateralis) and to a lesser extent the soleus muscles. During the ascent phase, the hip extensor moments of force produced the largest powers followed by the ankle plantar flexors and then the knee extensors. (2)

  • Description Backward push off with knee tuck into backwards layout

The hip and knee extensors provided the initial bursts of power during ascent with the ankle extensors and especially a second burst from the hip extensors adding power during the latter half of the ascent. (2).


  1. Jeni R. Mcneal , William A. Sands & Barry B. Shultz (2007) Muscle activation characteristics of tumbling take-offs, Sports Biomechanics,6:3, 375-390, DOI: 10.1080/14763140701491393
  • Slater, L. V., & Hart, J. M. (2017, March 1). Muscle activation patterns during different squat techniques. Latest TOC RSS.