Posts Tagged ‘grip strength’

Have you recently considered if wrist positioning affects grip strength?

Well, in case you have, this post is going to discuss some facts related to grip strength and wrist positioning.

So lets go through this demonstration to see if wrist positioning does affect grip strength. Working in the industrial setting, this is a demonstration that I will use with patients and other individuals to stress the importance of a neutral grip whenever possible.

So let’s take a look at the first example of grip with the wrist held in the neutral position. A neutral grip was able to generate 105 pounds of force. The second example shows the wrist at approximately 30 degrees of wrist flexion. Pay attention to the grip strength that is generated. The grip strength generated in this position is 68 pounds of force. 35% less than in neutral grip. The grip strength generated near end-range of flexion is 39 pounds of force. This is 63% less strength than generated in neutral grip and 43% less grip strength than generated in ~30 degrees of wrist flexion.

The conclusion: Grip strength generated in the flexed position is significantly less than compared to grip in the neutral position. The greater degree of flexion, the less strength that is able to be generated.

So the answer to the question is yes, wrist positioning does affect grip strength. Now, let’s look at some related information. This is of particular interest with those who have or treat carpal tunnel syndrome.

Extremes of wrist flexion and wrist extension can cause compression of the carpal canal and negatively affect intraneural blood flow. In an average person, pressure within the carpal canal is approximately 2 mm Hg.

When pressures reach 20-30 mm Hg, venular blood flow is impacted. Axonal transport is affected at 30 mm Hg. Neurophysiologic changes such as motor and sensory dysfunction begins at 40 mm Hg. At 60-800 mm Hg, complete cessation of intraneural blood flow is noted. Average carpal canal pressure in carpal tunnel patients in neutral wrist position was 32 mm Hg as reported in the study: The carpal tunnel syndrome: A study of carpal canal pressures. The same study goes on to show that extreme ranges of wrist flexion and extension in those with carpal tunnel syndrome increased carpal canal pressure in excess of 90 mm Hg.

One more aside. In the study: Segmental Carpal Canal Pressure in Patients With Carpal Tunnel Syndrome, the greatest pressure in the carpal canal was found 10mm distal to the distal wrist crease.

So as we bring this to a conclusion. Grip performed in a neutral grip is the optimal position for strength and also presents an environment for minimal carpal canal pressure. Grip performed in the flexion and extension is a less efficient movement and does contribute to increased pressure within the carpal canal.

So this is some information that you can store and utilize the next time you encounter someone using inefficient technique for their task or perhaps someone with carpal tunnel syndrome.

What do you think? Any new information that you would like to share? Any similar experiences that you can speak about to the group.

Additional Source: Carpal Tunnel Syndrome by David A. Fuller, MD


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