The Snap-Clip Attachment
Yoshio Setoguchi, M.D.
A new quick-disconnect type of clip fastener which can be used at any harness-attachment point has been developed by Carl Sumida at the Child Amputee Prosthetics Project at UCLA.
The snap-clip attachment consists of two pieces: a stainless-steel stud and a nylon clip. The clip has been made in three sizes which will accept webbing 1/2 in., 1 in., and 1 1/2 in. wide. The same size stud portion fits all three clip sizes. The stud can be attached to laminated shells, metal parts, and (with a washer backing) to polyethylene or other flexible materials. The nylon clip pivots freely on the stud, thus permitting the amputee movement with comfort. The snap-clip attachment will tolerate high loading. It lies flat under clothing and can be washed with the harness without concern for rusting. It can be used in combination with center-bar buckles, double D-rings, or four-bar buckles if desired. With this arrangement the harness can be detached by the amputee without change in its adjustment, while still providing easy adjustment by the prosthetist without removal of snaps or stitching.
Trials at the Child Amputee Prosthetics Project have shown that snap-clip attachments can be applied wherever snaps and buckles are currently used on prostheses. They have been used on Silesian bandages and on the chest and thigh straps of shoulder-disarticulation prostheses. The clips have been enthusiastically accepted by the amputees who have tried them. Easier independent donning and removal of the prostheses were possible for the bilateral shoulder-disarticulation patient who uses her mouth to place the chest strap and clip over the stud on the socket. She then expands her chest to secure the fastener (Fig. 1 ). She can grasp her thigh strap with her hook and push down to disconnect or connect the fastener at that point (Fig. 2 ).
When at first the clip seemed to be too tight for removal of the fastener by the amputee herself, the prosthetist enlarged the opening into which the stud slides. However, this enlargement caused inadvertent opening of the snap clip. The fit of the clip and stud are quite critical and should not be modified unless inadvertent opening can be tolerated. When fitted as they are currently made, the clips are more reliable than snaps.
Redesign and improved manufacturing have eliminated problems encountered with early prototypes. The present clips are injection-molded. This process produces a stronger, highly consistent product and, after the original cost of the mold has been amortized, large numbers of clips can be produced at low cost.
The snap-clip attachment was developed and the present stock produced under grant DHEW C-199 from the U.S. Children's Bureau. A limited supply of attachments can be made available gratis to other amputee centers on a "first come, first served" basis. Clinics wishing to try the snap-clip attachment and willing to provide feedback data on applications and experiences should indicate the size and number desired by writing to the author at Room 25-26, UCLA Rehabilitation Center, 1000 Veteran Ave., Los Angeles, Calif. 90024.
Yoshio Setoguchi is the Medical Director of the UCLA Child Amputee Prosthetics Project, West Los Angeles, California