Abstract
Mitigation of fall-related injuries for populations of transfemoral amputees fitted with a socket or an osseointegrated fixation is challenging. Wearing a protective device fitted within the prosthesis might be a possible solution, provided that issues with automated fall detection and time of deployment of the protective mechanism are solved. The first objective of this study was to give some examples of the times and durations of descent during a real forward fall of a transfemoral amputee that occurred inadvertently while attending a gait measurement session to assess the load applied on the residuum. The second objective was to present five semi-automated methods of detection of the time of descent using the load data. The load was measured directly at 200 Hz using a six-channel transducer. The average time and duration of descent were 242 ± 42 ms (145–310 ms) and 619 ± 42 ms (550–715 ms), respectively. This study demonstrated that the transition between walking and falling was characterized by times of descent that occurred sequentially. The sensitivity and specificity of an automated algorithm might be improved by combining several methods of detection based on the deviation of the loads measured from their own trends and from a template previously established.
| Abbreviations | ||
| E1 | = | time of heel contact |
| E2 | = | time of flat prosthetic foot |
| E3 | = | time of descent |
| E4 | = | time of toe-off and sliding of sound toe |
| E5 | = | beginning of descent of the prosthesis visible on video |
| E6 | = | beginning of impact |
| E7 | = | time of impact |
| BW | = | body weight |
| BWm | = | Body weight per meter |
| FAP | = | force applied on the antero-posterior axis |
| FML | = | force applied on the mediol-lateral axis |
| FLG | = | force applied on the long axis |
| MAP | = | moment applied around the antero-posterior axis |
| MML | = | moment applied around the mediol-lateral axis |
| MLG | = | moment applied around the long axis |
| TI | = | initial time delimitating regression line |
| TF | = | final time delimitating regression line |
| Abbreviations | ||
| E1 | = | time of heel contact |
| E2 | = | time of flat prosthetic foot |
| E3 | = | time of descent |
| E4 | = | time of toe-off and sliding of sound toe |
| E5 | = | beginning of descent of the prosthesis visible on video |
| E6 | = | beginning of impact |
| E7 | = | time of impact |
| BW | = | body weight |
| BWm | = | Body weight per meter |
| FAP | = | force applied on the antero-posterior axis |
| FML | = | force applied on the mediol-lateral axis |
| FLG | = | force applied on the long axis |
| MAP | = | moment applied around the antero-posterior axis |
| MML | = | moment applied around the mediol-lateral axis |
| MLG | = | moment applied around the long axis |
| TI | = | initial time delimitating regression line |
| TF | = | final time delimitating regression line |
Declaration of interest: The author reports no conflicts of interest. The author alone is responsible for the content and writing of the paper.