Shock-absorbing effects of various padding conditions in improving efficacy of wrist guards.
The use of wrist guards has limited efficacy in preventing wrist injuries during falling in many sports activities. The objectives of this study were to measure the ground reaction force of the hand under simulated impact of the forearm and hand complex with different padding conditions of wrist guards and to analyze their impact force attenuation and maximum energy absorption for improved functional efficiency. A total of 15 subjects, wearing a commercial wrist guard, participated in a cable-released hand impact experiment to test four different conditions on the volar aspect of the hand, which include a wrist guard without a volar splint (bare hand), with a volar splint (normal use), with a volar splint and additional viscoelastic polymeric padding, and a volar splint and additional air cell padding. The ground reaction force and acceleration of the hand were measured using a force platform mounted on an anti-vibration table and a miniature accelerometer, respectively. Additional padding on the bare hand could substantially improve the maximum energy absorption by more than 39%, with no differences with each other. However, only the air cell padding could simultaneously improve the impact force attenuation by 32% compared with the bare hand impact without compromising the maximum energy absorption. It is recommended that common wrist guard design should provide more compliant padding in the volar aspect to improve the impact force attenuation through optimal material selection and design. Key PointsTHE CONTROVERSIAL EFFICACY OF WRIST GUARDS IN PREVENTING WRIST INJURIES DURING FALLING WAS TESTED THROUGH INVESTIGATION OF THEIR IMPACT FORCE ATTENUATION AND MAXIMUM ENERGY ABSORPTION FROM THE MEASURED GROUND REACTION FORCE OF THE HAND UNDER SIMULATED IMPACT OF THE FOREARM AND HAND COMPLEX WITH FOUR DIFFERENT PADDING CONDITIONS OF WRIST GUARDS: a wrist guard without a volar splint (bare hand), with a volar splint (normal use), with a volar splint and additional viscoelastic polymeric padding, and a volar splint and additional air cell padding.In general, padding on the bare hand could improve the maximum energy absorption by more than 39%, while only the air cell padding could simultaneously attenuate the peak impact force by 32% without compromising the maximum energy absorption.Common wrist guard design requires more compliant padding in the volar aspect to improve the impact force attenuation, which should be done through optimal material selection and design.
Department of Factory Automation, Dongyang Technical College , Seoul, Korea.
Il-Kyu
IK
Hwang
Department of Mechanical Engineering, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin, USA.
Kyu-Jung
KJ
Kim
Accidental falls direction; fractures; prevention; wrist injuries