Wednesday, January 16, 2013

Weight Belts: Protective for the Lumbar Spine?

Lower back pain is the most popular claim for worker's compensation [1]. It also accounts for 40% of sick days used, which is second to the common cold. Several of my clients have started with chronic lower back pain and, truth be told, I used to have chronic lower back pain as well.

However, chronic lower back pain should not be a roadblock for those who want to strength train. Many with lower back pain use weight belts with the hope that the belt will serve as a reminder to lift properly, will reduce torso range of motion, and reduce the compressing forces on the lumbar spine by increasing pressure on the spine.

Is a weight belt effective in addressing these reasons? More importantly, does a weight belt offer protection for the lumbar spine during strength training?

Stuart McGill at Waterloo University in Ontario, Canada, is a leading researcher in the study of spinal biomechanics. McGill conducted a few studies looking at the specific effects of weight belts. The results of his research [2], as well as a few other researchers, are featured in the table below:

Research Finding
Significance of the Finding
1. Weight belts increase blood pressure in general, as well as blood pressure and heart rate during common lifts (deadlifts and the bench press) [2]. 
Weight belts could be detrimental for people who have high blood pressure and other cardiovascular health concerns.
2. Belts increase intra-abdominal pressure [2].
Increasing intra-abdominal pressure actually increases the compressive force on the lumbar spine, meaning there is a greater risk of injury [2]. (Increasing intra-abdominal pressure is also the major detriment of holding your breath during strength training).
3. Two studies found no reduction in the load lifted by lumbar extensors [3, 4].
Weight belts provide no assistance for some of the major lower back muscles.
4. Belts decrease spinal rotation but not spinal flexion [2].
The two actions that put the spine in a great risk for injury are twisting and slumping over (flexion). A belt does not offer any protection for one of those movements.
5. People lift more weight when using weight belts [2].
Belts give lifters a false sense of security. If their technique is poor, increasing the resistance will increase the risk of injury.

Strength Training with Lower Back Pain

Looking at the table, weight belts seem to provide one major benefit (limiting rotation). On the other hand, they provide no protection from another vulnerable movement (flexion), pose an additional threat for the cardiovascular system, and provide a sense of overconfidence that could increase orthopedic or muscular injury risk. 

Overall, I don't advocate the use of a weight belt. So what can a person do when strength training to prevent back injury or to prevent the worsening of an existing back injury? Here are my two suggestions:

  1. Keep your upper torso in the same position during an exercise. If you're seated upright with a slightly arched back, then stay in that position. If you're slightly slumped over, stay in that position. Some exercises (crunches, lower back extensions, etc.) require your torso to flex and extend. If that's the case, move gradually between positions. The worst action to take is arching or slumping your back in a fast, jerky motion to assist in performing a rep.
  2. As demonstrated in the picture below, lift a weight from below your waist by keeping your chest up and looking forward (instead of down). This position will prevent the spine from becoming flexed, or slumped, which increases the compressive force on your spine. 

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