how much force can thumb joint withstand?
How much force can the thumb joint withstand before becoming dislocated or separated? I'm thinking of the kind of force that be applied by a thumb ring pulling a bowstring.
Justin,
There are so many variables in a question like that. Some of them are the health of the individual, the condition of the tendons and connective tissue and also the size of the thumb.
I doubt that strength of the arms and shoulders is sufficient to dislocate the thumb of a healthy archer in a normal draw. That is to say, if you can draw the bow, your thumb should be able to take the strain. You might be able to dislocate the thumb if you trapped it in a badly formed ring that concentrated pressure on one part of the thumb joint. I often wonder what would happen using a Korean male ring that was too tight with a super heavy bow. More standard rings would tend to come off or force the thumb open if the string pressure becomes too great.
If you look at the thumb as a right angle hinge, it is more likely to be forced open rather than break. If you were using an unsupported thumb, not locked against the middle finger, and were holding it down by the strength of the index finger, the force could be shifted to the distal joint of the thumb. This would be very uncomfortable and I suggest the average person would let go before any injury was done.
I once unsuccessfully tried to draw a 135 lb longbow. It was not my thumb that felt stressed, it was my left elbow and shoulders.
There are so many variables in a question like that. Some of them are the health of the individual, the condition of the tendons and connective tissue and also the size of the thumb.
I doubt that strength of the arms and shoulders is sufficient to dislocate the thumb of a healthy archer in a normal draw. That is to say, if you can draw the bow, your thumb should be able to take the strain. You might be able to dislocate the thumb if you trapped it in a badly formed ring that concentrated pressure on one part of the thumb joint. I often wonder what would happen using a Korean male ring that was too tight with a super heavy bow. More standard rings would tend to come off or force the thumb open if the string pressure becomes too great.
If you look at the thumb as a right angle hinge, it is more likely to be forced open rather than break. If you were using an unsupported thumb, not locked against the middle finger, and were holding it down by the strength of the index finger, the force could be shifted to the distal joint of the thumb. This would be very uncomfortable and I suggest the average person would let go before any injury was done.
I once unsuccessfully tried to draw a 135 lb longbow. It was not my thumb that felt stressed, it was my left elbow and shoulders.