Kinesiology THURSDAY – Biomechanics of a Wrist Jam

Full body of focused fit female in sportswear doing push ups on mat during fitness workout in sports studio

Have you ever tried to do a push-up or any activity which required planting your hands on the floor only to feel a “jam” or pain in your wrist? This problem is fairly common and often ignored. You are able to perform most functional moves without having to achieve full, end range wrist extension. But your body was also designed to be able to bear weight through your hands without wrist pain.

Look at the small carpal bones of the wrist. Here is what has to happen for normal wrist extension to occur:

The proximal row of carpal bones moves volarly (convex moving on a concave surface), with the scaphoid being the primary bone articulating with the distal radius
The capitate and hamate (distal row) move volarly
The trapezium and trapezoid (distal row) move dorsally

If your hand is fixed on the ground (closed-chain position), the relative movement is still the same, only it is the radius that moves dorsally on the proximal row of carpal bones.

Here’s a video on how to identify each of the carpal bones. It’s easier than you think.

Another consideration is the position of the radius. There is no radial movement required for wrist extension, however, if the radius positioned slightly anteriorly or posteriorly, this may result in a wrist jam.

Here’s a video on how to assess radial head position at the elbow.

When things go wrong…

Sometimes with prolonged shortening of the wrist and finger flexors or after an injury that requires mobilization, capsular restrictions may limit movement of the carpal bones causing a jamming sensation in the wrist.

Mobilizations of the carpal bones, specifically the scaphoid, may help restore normal wrist extension. Correction of radial head position may also help.

In addition, stretching the wrist flexors or releasing the fascia on the volar forearm may help normalize carpal bone movement. But remember, only stretch if it feels like a stretch.

Why does this matter?

Wrist extension is a necessary motion if you ever need to plant your hand on any surface. The limitation is often ignored or the motion just avoided, but it shouldn’t be. In most cases, this wrist jam is fixable. Don’t ignore the wrist bones.

Because nobody has time to be in pain.

Until next time…