Determination of the rotary flexibility of the elbow joint

Summary

A method of determining quantitatively the rotary flexibility of the elbow joint was developed and its reliability tested. Examinations of the left elbow joint of 100 healthy men between the ages of 18 and 72 were performed, consisting of measurements of passive supination effected by a graduated external torque as well as of active supination and pronation. The purpose of the study was to acquire a norm as basis for the functional evaluation of this joint in playing the violin. The investigation produced the following results:

• 1. The maximum active range of movement consists of about 160‡, the supinatory portion is generally higher than the pronatory, when related to a zero position with the palm of the hand in the sagittal plane.

• 2. The range of passive movement is non-linearly dependant on the external torque.

• 3. The variability of passive flexibility increases with decreasing external torque and is generally higher than the variability of active flexibility. Active pronation varies more than active supination.

• 4. A close positive correlation between active and passive supination is evident only when a higher torque is applied. The correlation between active supination and active pronation is only 0.33.

• 5. The statistically establishable reduction of flexibility through ageing is not considered to be characteristic of actual conditions. On the other hand, a broader dispersion is clearly recognizeable as the result of ageing, through a drop in the lower limit of deviation.