A known limitation of tether lanyards is fastening and unfastening the tether from the liner, which needs to be performed to clean or replace the liner and can be difficult for some users.
Researchers conducted a study aimed to create a quick connect that allows users to easily attach and detach the tether from the liner.
A slide-and-lock mechanism was used for the study. To operate the quick connect, the prosthesis user turns open the lock, slides it onto a short pin extending from the liner, and releases the mechanism, causing it to spring back to the locked position. Mechanical tests demonstrated that the system well tolerated tensile loads of 25,000 cycles at 100 N and single cycles at 350 N.
Five people with transtibial amputations trialed the system and took between two and 30 seconds to fasten and unfasten the quick connect. While the users found the quick connect intuitive to use, secure, relatively quiet, and stable, they preferred their traditional pin lock over the quick connect system. Their preference was influenced by the multistep procedure (twist-align-slide) required with the quick connect that they considered more complex than operating the locking pin to which they were accustomed.
In its current form, the quick connect is likely to be used by limited community ambulators who struggle with the pin lock donning procedure. It also has potential use with powered tethers that use a motor to adjust tether length, the study found.