Understanding the effects of suspension systems on lower-limb prosthesis rotation
File(s)
Published online version
Author(s)
Lim, Xing
Clark, Angus B
Bull, Anthony MJ
Type
Journal Article
Abstract
Background:
Limb rotation within prosthetic sockets significantly affects the comfort, gait, and stability of lower-limb amputees. Despite advancements in suspension systems, empirical evidence validating their rotational control remains limited. This study aims to systematically compare the rotational resistance of 3 prosthetic suspension systems—Pin-Lock, Suction, and Hook-and-Loop (HOLO)—under controlled conditions, addressing a critical gap in prosthetic design research.
Methods:
We evaluate the rotational resistance of 3 different prosthetic suspension systems—Pin-Lock, Suction, and HOLO—under varying axial loads (0/40/80 kg) and both (medial and lateral) rotational directions. Using a custom-designed mock limb and identical 3D-printed sockets, each suspension system was evaluated using a materials testing machine. The angular displacement of the limb inside each socket was measured under a constant torque ramp of 1 Nm/s, up to a maximum torque of 8.5 Nm.
Results:
The HOLO system (9.67° at 80 kg) showed significantly less rotation than the Pin-Lock (13.34° at 80 kg, p < 0.01) and Suction (14.42° at 80 kg, p < 0.01) systems. The medial rotation was 10.5% and 26.9% less than lateral rotation for Pin-Lock and HOLO systems, respectively, and 25.5% greater for Suction (all p < 0.01). Increasing axial loads reduced rotation for the Pin-Lock system only.
Conclusions:
This is the first study to measure the effectiveness of different prosthetic suspension systems using a representative mock limb. The results show that there are significant differences between the systems, highlighting the need to consider a user's activity level and rotational demands in prosthetic provision.
Limb rotation within prosthetic sockets significantly affects the comfort, gait, and stability of lower-limb amputees. Despite advancements in suspension systems, empirical evidence validating their rotational control remains limited. This study aims to systematically compare the rotational resistance of 3 prosthetic suspension systems—Pin-Lock, Suction, and Hook-and-Loop (HOLO)—under controlled conditions, addressing a critical gap in prosthetic design research.
Methods:
We evaluate the rotational resistance of 3 different prosthetic suspension systems—Pin-Lock, Suction, and HOLO—under varying axial loads (0/40/80 kg) and both (medial and lateral) rotational directions. Using a custom-designed mock limb and identical 3D-printed sockets, each suspension system was evaluated using a materials testing machine. The angular displacement of the limb inside each socket was measured under a constant torque ramp of 1 Nm/s, up to a maximum torque of 8.5 Nm.
Results:
The HOLO system (9.67° at 80 kg) showed significantly less rotation than the Pin-Lock (13.34° at 80 kg, p < 0.01) and Suction (14.42° at 80 kg, p < 0.01) systems. The medial rotation was 10.5% and 26.9% less than lateral rotation for Pin-Lock and HOLO systems, respectively, and 25.5% greater for Suction (all p < 0.01). Increasing axial loads reduced rotation for the Pin-Lock system only.
Conclusions:
This is the first study to measure the effectiveness of different prosthetic suspension systems using a representative mock limb. The results show that there are significant differences between the systems, highlighting the need to consider a user's activity level and rotational demands in prosthetic provision.
Date Issued
2026-03-13
Date Acceptance
2025-12-15
Citation
Prosthetics and Orthotics International, 2026
ISSN
0309-3646
Publisher
Lippincott, Williams & Wilkins
Journal / Book Title
Prosthetics and Orthotics International
Copyright Statement
© 2026 The Authors. Published by Wolters Kluwer incorporated on behalf of The International Society for Prosthetics and Orthotics. This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/41820258
PII: 00006479-990000000-00410
Subjects
lower-limb
prosthetics
rotation
suspension
Publication Status
Published online
Coverage Spatial
France
Date Publish Online
2026-03-13