THE string may hit the right thumb of the archer because of bad loosing, wherein the archer leaves his thumb folded to his palm. It can be avoided by opening the thumb fully to its back.
The tip of the thumb may turn black and blue because of two things. The first is the rubbing of the string over it at the time of loosing. This can be avoided by opening the thumb fully to its back. The second is the placing of the string between the crease of the knuckle and the end of the thumb, with the result that the blood clots in the tip and turns it black and blue. This can be avoided by placing the string close to the groove if, indeed, the archer's method be not that of placing it directly in the groove itself.
The nail of the right thumb may turn black and blue or even be broken because of one of four things. The first is the placing of the index finger upon the nail of the thumb and the string upon the flesh opposite as the archer locks his fingers in the clench. The pressure of the draw will then fall upon the nail and the blood may clot under it or it may even be broken. This can be prevented by placing the index finger upon the back of the thumb just below the nail and upon one third of the nail[26].
The second cause of injury is releasing the thumb sooner than the, index finger at the moment of loosing, with the result that the finger rubs heavily on the nail and causes it to become black and blue or even to break. This can be avoided by releasing the index finger sooner than the thumb. The third is the rubbing of the thumb stall against the string; and the fourth is either an excessively long thumb stall or one that is too short.
The thumb of the left hand may be blistered or wounded, when the arrow is loosed, in any one of three places: on the lower phalanx, on the upper phalanx, and on the flesh projecting from between the bases of the index finger and thumb.
The injury to the lower phalanx of the thumb may result from one of three things: first, from too thin a grip and too large a hand; second, from a poor manner of grasping the grip; third, from greater stiffness in the bending of the lower limb which consequently overbalances the upper limb.
These can be remedied as follows: in the case of the thin grip by wrapping a tape of leather or cotton around the grip; in the case of the poor manner of grasping the grip by rectifying it according to the directions given in Section XVI; in the case of imbalance by warming the lower limb a little over a slow fire until it is corrected, if the difference be small, or by reducing it with a file if the fire should fail to rectify it.
Injury to the upper phalanx of the thumb may result from any one of three things: from rigidity of the thumb and index finger while grasping the grip; from raising the upper phalanx of the thumb while drawing; and from placing the thumb upon the index finger while performing the same operation of drawing.
These can be remedied by relaxing the thumb and index finger if they be rigid; by lowering the upper phalanx of the thumb if it be raised; and by evening up the index finger and thumb if the latter be placed upon the former, so that they will then form the lock of thirty.
Injury to the flesh projecting at the base of the left thumb and index finger may result from one of three things: from wrongly holding the grip hard and deep into the palm; from nocking the arrow too low on the string; and from too small and narrow a nock in the arrow.
These can be remedied by rectifying the hold on the grip in accordance with the manner described in Section XVI, by nocking the arrow higher on the string,, and by enlarging the nock of the arrow if it be too small.
The flesh at the base of the thumb and index finger may be injured from roughness of the feathers. This can be avoided by nocking the arrow a little higher on the string.