The Body Mechanics Study That Matters

My body was broken. The diagnosis from the orthopedist confirmed it. He said, “You have cubital tunnel syndrome, cervical radiculopathy and an unstable shoulder.

“My advice?” he continued. “Quit massage.”

I appreciated his concern, but I wasn’t looking for career counseling. True, I had 20 years of wear and tear on my body as a massage therapist, but that was also 20 years of experience with figuring out how to work around injuries and pain. So, I made this deal with myself: You have a year to figure out how to massage without being in pain or you hang up your hands.

Everything was on the table. I tried new body-saving strategies and jettisoned any technique that triggered or exacerbated one of my conditions, even if I had been doing the technique my entire massage career. I also scoured the internet for information that could help me, and that’s when I found Ed Mohr, CPE, CSP, NCTM’s research, Proper Body Mechanics From an Engineering Perspective, published in the Journal of Bodywork and Movement Therapies in 2010. The research included a computer modeling test and a field study.1

In his research, Mohr sought to find the optimal body mechanics for applying force to a client while sparing the massage therapist’s body.

Stacked Joints Versus Not Stacked Joints

Here’s a question Mohr’s research answered for me: When applying deep pressure, should you (a) bend your elbow or (b) keep it straight?

You might be thinking this is a trick question and it doesn’t matter if your elbow is straight or bent, but there is a correct answer—it’s b, straight elbow.

Why?

In the computer modeling study, Mohr created two categories of body mechanics to compare: improper and proper/correct.

The improper method meant the massage therapist was bending at the torso while standing in an asymmetrical stance (one leg in front of the other) and applying force through an arm that was bent at the elbow.

massage therapist with improper posture
Improper posture

The proper/correct method meant the massage therapist was in an asymmetrical stance, but the back leg was locked, which put the ankle, knee, hip and back in a straight line. Also, the arm that was applying force was straight, putting the shoulder, elbow and wrist in alignment. Mohr refers to joints being in alignment as stacking joints.

Mohr then input a compressive force requirement (40 pounds), which could be viewed as the amount of pressure a client wants, as well as the measurements and proportions of the population he was testing, which was a female therapist of average size.

How did the bent elbow do?

Not so well.

In fact, the bent elbow was a “significant limiting joint with only 60% (of the test population) having the required capability” to generate the compressive force requirement.2

Why is a straight arm better than a bent arm?

Mohr explains: “When a joint is stacked (in straight alignment), forces acting on the joint go straight through, and do not generate any rotational force that must be counteracted by the muscle.”3

Alternately, leaning with a bent elbow requires more stabilization—more muscle work—which leads to faster muscle fatigue.

To get a feel for stabilizing your body weight with stacked joints versus joints that aren’t stacked, try this:

1. Get in the start position for a push-up with arms straight.

2. Now time how long you can stay there.

3. Next, get into the down position for a push-up where your arms are bent and your chest is close to the ground. You don’t even need to get out the stopwatch to know the bent elbow position is going to be the loser—big time.

massage therapist showing proper posture
Proper posture

Lean to Generate Force

This next finding of Mohr’s research validated what I had experienced in my year-long mission to massage pain-free. It was that leaning to apply pressure was more efficient and easier on your body than pushing with your arms.

If you’re leaning, you are transferring your body weight onto the client by shifting your weight to the front of your feet. From an efficiency standpoint, it’s hard to see a downside to leaning. As Mohr points out in his study, “body weight and gravity are free.”4 The therapist just needs to guide her body weight onto the client and then stabilize it. Yes, some muscle activity is required when stabilizing body weight, but Mohr concludes that it’s minimal.

If you’re not a leaner and haven’t experienced the ease with which you can generate force, then you’ll want some numbers to back up the claim.

Mohr had 18 massage therapists use an Ergo-FET digital palm force gauge to record maximum force as they applied a compressive force of 40 pounds at a 45-degree angle to the edge of a massage table facsimile. The application heights were 39.5 inches, 34.5 inches and 29 inches.

Then he compared maximal force output for three positions: poor (standing arm push with no to minimal leaning; good (leaning in an asymmetrical stance, joints stacked, back leg not locked; and best (leaning in an asymmetrical stance, joints stacked, back leg locked).

Good position and best position beat poor position by 12% and 34% respectively.5 If you’re wondering why best position beat good position, it’s because leaning with a locked back knee in an asymmetrical stance allows the therapist to effectively push from the back foot to generate additional force.

Mohr’s findings of leaning, stacking joints and locking the back knee (when in an asymmetrical stance) to produce optimal force with minimal strain helped me in my quest to find the best body mechanics for me, but there’s a caveat here that Mohr acknowledges. His research does not answer what the best table height is for you.

massage therapist in parallel foot stance
Parallel foot stance

Asymmetrical and Parallel Foot Stances

Mohr says that body types and massage styles—whether you primarily use your forearms or hands to massage—will be factors in your proper table height determination.

I agree and I would add another consideration under the massage styles heading: Do you use a parallel-foot stance in addition to an asymmetrical stance? An example of the parallel-foot stance would be when the massage therapist is facing the massage table with her feet parallel to each while she’s doing ischemic compression in the thoracic lamina groove.

If you’re in a parallel-foot stance you have no back leg to push from. So, if you’re doing deep pressure, you’ll need a lower table to leverage your body weight onto the client.

In an AMTA video (youtube.com/watch?v=asP4qZ0bx4w), Mohr correctly points out that a low table can compromise a low back, but there’s a workaround for that—use the massage table for support.

For now, if you’re in pain when doing massage, try leaning and stacking your arm joints to apply pressure. It will be easier on your upper body than pressing with your arms. If you’re in an asymmetrical stance, either facing the table or alongside of the table, lock your back knee and push from your back foot to produce more force. Now, let your experiment to massage pain-free begin.

Mark Liskey

About the Author:

Mark Liskey is a massage therapist, massage CE provider and author of “The Pain-Free Massage Therapist,” a body-mechanics strategies and techniques book for eliminating pain in the massage room and extending massage careers. You can access free, instructional body-mechanics videos at painfreemassagetherapist.com.

Footnotes

1. Mohr EG, Proper body mechanics from an engineering perspective, IJTMB. 2010; Vol. 14(2).

2. Mohr EG, Proper body mechanics from an engineering perspective, IJTMB. 2010; Vol. 14(2):142

3. Mohr EG, Proper body mechanics from an engineering perspective, IJTMB. 2010; Vol. 14(2):141

4. Ibid.

5. Mohr EG, Proper body mechanics from an engineering perspective, IJTMB. 2010; Vol. 14(2):145


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