Kettlebells-Journal Strength Cond Res-Jan 2012-McGill

Posted by Kevin G. Parker, D.C.

Comment from me-For now-this is the FIRST published study of tissue loads during kettlebell exercises.

J Strength Cond Res.  2012  Jan;26(1):16-27.

Pub Med. Gov Link

Kettlebell swing, snatch, and bottoms-up carry:  back and hip muscle activation, motion, and low back  loads.

McGill SM, Marshall LW.

Spine Biomechanics Laboratories, Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada.

Abstract

The intent of this study was to quantify spine loading during different kettlebell swings and carries.

No previously published studies of tissue loads during kettlebell exercises could be found.

Given the popularity of kettlebells, this study was designed to provide an insight into the resulting joint loads.

Seven male subjects participated in this investigation.

In addition, a single case study of the kettlebell swing was performed on an accomplished kettlebell master.

Electromyography, ground reaction forces (GRFs), and 3D kinematic data were recorded during exercises using a 16-kg kettlebell.

These variables were input into an anatomically detailed biomechanical model that used normalized muscle activation; GRF; and spine, hip, and knee motion to calculate spine compression and shear loads.

It was found that kettlebell swings create a hip-hinge squat pattern characterized by rapid muscle activation-relaxation cycles of substantial magnitudes (~50% of a maximal voluntary contraction [MVC] for the low back extensors and 80% MVC for the gluteal muscles with a 16-kg kettlebell) resulting in about 3,200 N of low back compression.

Abdominal muscular pulses together with the muscle bracing associated with carries create kettlebell-specific training opportunities.

Some unique loading patterns discovered during the kettlebell swing included the posterior shear of the L4 vertebra on L5, which is opposite in polarity to a traditional lift.

Thus, quantitative analysis provides an insight into why many individuals credit kettlebell swings with restoring and enhancing back health and function, although a few find that they irritate tissues.

Other good Kettlebell or McGill articles:

Kettlebells for Injury Rehab

Kill the sit-up crunch-Dr. Stuart McGill

No Sit-ups Stuart McGill PhD

If you are suffering from: Sports Injuries, Sprains, Strains, Car accident,  Herniated Disc, Disc Bulge, Degenerative Disc Disease, Neck pain, Headaches, Low back pain, of just want to feel better and have better life performance– please call our office in Irvine, California- at 949.857.1888 or visit our website at ADJUST2IT to learn more about Functional Fitness Chiropractic, Sports massage, Myofascial Release, Corrective Exercise, Non Surgical Spinal Decompression, Class IV laser,  and Functional Nutrition.

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