Objective In transtibial hybrid sockets, a small amount of weight is tolerated by the patellar tendon. The spandex anti-friction pad is designed with two fabric layers that minimize the friction between them; therefore, its use may reduce the pressure on the patellar tendon in transtibial amputees. In this study, we aim to evaluate the effect of using spandex anti-friction pad within a transtibial hybrid socket on the standing and walking duration, satisfaction, and pain in the patellar tendon of unilateral transtibial amputees (UTTAs). 
Materials & Methods In this pilot study, 16 eligible UTTAs using the hybrid sockets were selected using a convenience sampling method. The duration of standing on the prosthetic leg (using the one-leg standing balance test [OLSTP]), the duration of walking on the treadmill, pain (using the VAS), and satisfaction with the prosthetic leg (using the orthotics and prosthetics user’s survey [OPUS]) were examined. Then, the participants used the anti-friction pad within their prosthetic sockets for one week. After that, the post-test assessments were conducted. The paired t-test was used for comparing variables with normal distribution (OPUS score and duration of walking on the treadmill) and the Wilcoxon test was used for those with abnormal distribution (VAS and OLSTP scores). The SPSS software, version 26 was used to analyze the data.
Results The participants showed a significant reduction in VAS score (P<0.001) and a significant increase in the OPUS score (P<0.001) after using the anti-friction pad. Moreover, the results showed a significant effect on increasing the OLSTP score (P<0.001) and the duration of walking on the treadmill (P<0.001).
Conclusion The use of spandex anti-friction pad, for reducing the pressure and friction between the socket and the stump, may reduce pain and increase the satisfaction and comfort of transtibial prosthesis users. It can also help them walk greater distances and stand on their prosthetic leg longer. However, to confirm these findings, further studies are needed.