Furniture sliders are extremely inexpensive (less than $10 at Lowes) and extremely versatile. I was inspired by Ross from Ross Training to experiment with these tools. One of my favorite exercise progressions is a multi-planar single leg squat. The slider is a great cue to promote mobility and stability as well as adding flow to a sequence of movements. It easily allows progressions and regressions based on the needs of the individual.
Category Archives: Core
Sometimes I forget how long the debate over abdominal hollowing (drawing in) vs. bracing has been going on. We’re close to 20 years on this topic. A year and half ago I started writing a clinical commentary on a herniated lumbar disc rehabilitation protocol which included addressing this very topic. A recent resurgence in interest regarding core stability (I guess it never really goes away) made me want to pull an excerpt from the article before it is published. I believe there is a time and a place for abdominal hollowing and abdominal bracing, but there is also a time for neither. The “neither part” has further been bolstered by my experience with Gary Gray’s Applied Functional Science (See Learning about Movement – Part 1). Here is the excerpt:
“Selective recruitment of the TA and multifidi utilizing “abdominal hollowing” or “drawing in” has been described in the literature and is widely practiced. (88,90) In contrast, the simple “abdominal bracing” exercise is another common exercise which not only emphasizes TA and multifidi recruitment, but has demonstrated recruitment of other musculature of the abdominal wall including the internal and external obliques.(89,91) Hodges et al.(85) have demonstrated, using an in vivo porcine model, some increased intervertebral stiffness utilizing TA activation by replicating “hollowing”, more recently, authors have demonstrated that this increased stiffness from “hollowing” is significantly less than during “abdominal bracing” due to decreased activation of the remainder of the abdominal wall musculature. (91,92) When sudden posterior trunk perturbations are introduced, abdominal bracing yielded significantly greater cocontraction of the trunk musculature, increased trunk stability, and better resistance to lumbar displacement than abdominal hollowing.(93) It also appears that the greater the conscious effort utilized to activate the muscular wall, the greater the decrease in spinal stability.(94) Abdominal hollowing has been shown to cause sufficient inhibition of the erector spinae and other musculature to decrease anterior pelvic during hip extension.(95) Inhibition of the erector spinae may have specific therapeutic and treatment benefits in addressing potential muscular imbalances, however they are valuable contributors to stable functional movement, which may result in decreased pelvic control if inhibited.
Although cocontraction of the TA and multifidi has been perceived as vital for muscular stabilization of the lumbar spine, their attempted selective activation may decrease anteroposterior trunk stability,(91-94) theoretically placing rotational trunk stability at risk through decreased activation of the external obliques in comparison to abdominal bracing.(89,91) Despite this, utilizing “hollowing activity” in the early in treatment phases of treatment can provide some symptom relief, kinesthetic awareness, motor control education, and provide some early activation of the TA and multifidi during the acute phase. However, once an individual progresses to postures that involve weight bearing, utilization of bracing may be better to enhance multiplanar stability.
Ultimately, conscious efforts towards bracing and/or hollowing do not contribute toward functional stability, rather, focus should be redirected towards addressing specific motor patterns utilizing multiple muscles in order to develop comprehensive spinal stability.(96) Moreover, from a theoretic functional perspective, consciously constraining movement in any region of the body over an extended period of time may alter the demands placed upon numerous other regions of the body. This may be best illustrated with the influence of external fixation, such as the use of a spinal orthosis for reducing pelvic mobility,(97) single segment spinal fusion influencing segmental motion around it,(98) and the increased risk of degeneration above and below the segment of lumbar fusion.(99) Although these examples entail extreme measures of stabilization beyond the level produced consciously by an individual, it serves as a reminder that a balance between mobility and stability is necessary to enable responses to the dynamic demands during movement of the human body.”
85. Hodges P, Kaigle Holm A, Holm S, et al. Intervertebral stiffness of the spine is increased by evoked contraction of transversus abdominis and the diaphragm: In vivo porcine studies. Spine (Phila Pa 1976). 2003;28(23):2594-2601. doi: 10.1097/01.BRS.0000096676.14323.25.
88. Richardson CA, Jull GA. Muscle control – pain control. what exercises would you prescribe? Manual Therapy. 1995(1):2-10.
89. Richardson CA, Snijders CJ, Hides JA, Damen L, Pas MS, Storm J. The relation between the transversus abdominis muscles, sacroiliac joint mechanics, and low back pain. Spine (Phila Pa 1976). 2002;27(4):399-405.
90. Hides J, Wilson S, Stanton W, et al. An MRI investigation into the function of the transversus abdominis muscle during “drawing-in” of the abdominal wall. Spine (Phila Pa 1976). 2006;31(6):E175-8. doi: 10.1097/01.brs.0000202740.86338.df.
91. Grenier SG, McGill SM. Quantification of lumbar stability by using 2 different abdominal activation strategies. Arch Phys Med Rehabi. 2007;88:54-62.
92. Stanton T, Kawchuk G. The effect of abdominal stabilization contractions on posteroanterior spinal stiffness. Spine (Phila Pa 1976). 2008;33(6):694-701. doi: 10.1097/BRS.0b013e318166e034.
93. Vera-Garcia FJ, Elvira JL, Brown SH, McGill SM. Effects of abdominal stabilization maneuvers on the control of spine motion and stability against sudden trunk perturbations. J Electromyogr Kinesiol. 2007;17(5):556-567. doi: 10.1016/j.jelekin.2006.07.004.
94. Brown SH, Vera-Garcia FJ, McGill SM. Effects of abdominal muscle coactivation on the externally preloaded trunk: Variations in motor control and its effect on spine stability. Spine (Phila Pa 1976). 2006;31(13):E387-93. doi: 10.1097/01.brs.0000220221.57213.25.
95. Oh JS, Cynn HS, Won JH, Kwon OY, Yi CH. Effects of performing an abdominal drawing-in maneuver during prone hip extension exercises on hip and back extensor muscle activity and amount of anterior pelvic tilt. J Orthop Sports Phys Ther. 2007;37(6):320-324.
96. Kavcic N, Grenier S, McGill SM. Determining the stabilizing role of individual torso muscles during rehabilitation exercises. Spine (Phila Pa 1976). 2004;29(11):1254-1265.
97. Konz R, Fatone S, Gard S. Effect of restricted spinal motion on gait. J Rehabil Res Dev. 2006;43(2):161-170.
98. Schwab JS, DiAngelo DJ, Foley KT. Motion compensation associated with single-level cervical fusion: Where does the lost motion go? Spine. 2006;31(21).
99. Putzier M, Hoff E, Tohtz S, Gross C, Perka C, Strube P. Dynamic stabilization adjacent to single-level fusion: Part II. no clinical benefit for asymptomatic, initially degenerated adjacent segments
after 6 years follow-up. Eur Spine J. 2010;19(12):2181-2189. doi: 10.1007/s00586-010-1517-4.