crutch for shortened forearm

Project  / Project number: 712  /  Status:

case712 v6-d27793e9

The challenge

Paradoxically crutches are used  on the contralateral side to relieve the pressure, hence our client got little benefit from using an elbow crutch on her right side whereas a  weight bearing walking aid  on her left side would be helpful. The initial referral was for a modified rollator but this was excluded due to lack of space and could not be used upstairs. In addition it did not suit weight bearing and her forearm could not be retained in the socket. Next the socket was transferred to a gutter arm crutch which also presented problems with retaining her arm in the socket and was “unwieldly” ie clumsy & difficult to use. Finally the socket was mounted vertically  to the hand grip of a standard elbow crutch. This optimised weight bearing as her body weight was transferred downwardsin a vertical direction . A tight fitting arm cuff was needed to secure the crutch to her arm and prevent it coming out when it was lifted up to move forwards. The end result enabled easy use and used in conjunction with her right sided crutch , she can now walk easily with minimal discomfort from her arthritic right hip. 

The solution

(1) Measurements of her left forearm were supplied by the client: overall length from elbow : 12cm, max circumference: 22cm, min circ: 12.5cm

(2) wooden former was turned from soft wood to these measurements – resembling a truncated cone (see opposite) .

(3) 1.5mm  sheet aluminium was carefully bent round the former (with difficulty) until it completed a circle , and both ends trimmed to give a flat edge then cut in half to give two equal sides of a shell .

(4) Starting 2.5cm up from the lower ends, the insides were lined with 10mm thick foam based padding using contact adhesive, allowing plenty of material to be folded back over at the top end.

(5) the two halves of the shell were re-united using gaffer tape

(6) the bottom end of the shell was plugged using the 2.5cm long segment from the wooden former , with a series of screws around the lower edge .

(7) the overhanging lining material was turned back over the exterior at the top end , stuck down and the whole shell covered with leatherette material .

(8) 5.5mm diameter hole was drilled through the centre of the wooden plug and 60mm  M5 bolt fitted which secured it to the hand grip of the crutch in a vertical position.

(9) wooden “bridging” piece was fashioned to secure the the top end of the shell to the crutch upright strut and held by an elasticated strap.

(10) the existing top half of the crutch with the plastic cuff  was replaced by a short length of 22mm aluminium tubing.

(11) the circumference of her upper arm was  measured and found to be very close to a standard 750ml paint tin which was used as a former.   0.8 mm aluminium was easily bent round into a complete circle -12cm long. A wooden “bridge” was fashioned which joined the aluminium cuff to the new upper crutch support . The cuff was attached by four c/s screws to the wooden bridge and lined with 10mm foam backed padding .

(12)the velcro strap from the redundant gutter arm crutch was transferred to the new cuff , which was now more flexible than the standard plastic cuff  and allowed the cuff to be tensioned more effectively. 

The benefit

It was difficult to get a snug fit for the forearm into the shell ie be comfortable under direct pressure and still be firm enough to be retained against gravity. In fact her forearm did not full fully reach the end of the shell  but it was comfortable and her forearm bones pressing against the sides of the shell provided a firm basis for weight bearing. The cuff had to be maximally tightened against her skin to prevent slippage (clothing had to be peeled back) .

Her first few steps were understandably hesitant as she had never used her left forearm previously but used in conjunction with her other crutch she was soon walking well and (virtually) pain free. This arrangement was much better suited for use around the house-both upstairs & downstairs than the two earlier options. For use outside, she planned to purchase a warm poncho  as  she would not be able to wear a coat with sleeves as previously.  In addition to  improving her mobility with much reduced discomfort, she was delighted  the new crutch would ensure a normal rehabilitation programme after her operation when the use of two crutches would be an essential stage of her recovery, which had been a major concern to her & her husband. .

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