As the world’s population ages, it is expected that the number of people having experienced amputations will grow, alongside comorbidities. Lifestyle adaptations associated with lower limb amputation are likely to occur and, with this, there is likely an impact on mobility and balance.
This research has initially investigated, via a comprehensive survey, the impact of lower limb amputation and prosthetic use on the lives of amputees with a focus on their balance and mobility during daily activities. The survey consisted of parts of the Prosthesis Evaluation Questionnaire (PEQ), the Activities-Specific Balance Confidence (ABC) Scale, and the Oswestry Disability Index (ODI). The results of the survey (155 participants in all levels of lower limb amputation) showed that the majority of LLAs suffered from stump and intact-side pain, frequent falling, LBP with impact on their functionality, and a lower level of balance confidence. A considerable proportion of respondents were at risk of falling and needed intervention to improve their balance.
According to the mentioned problems which LLAs deal with on a daily basis and the effectiveness of insoles use on similar balance problems and lower limb pains among non-amputees, it was supposed the insoles used on the intact side of LLAs would improve their situation. Therefore, biomechanical research was conducted to examine the effect of insoles use on perturbed standing balance and self-selected speed walking of TF amputees (11 participants) and a group of non-amputees (14 participants). Data was collected via 3D motion analysis systems, including high-speed cameras and force platforms. The function level of amputee participants was evaluated according to spatio-temporal variables of their walking and their responses to the ABC scale and PEQ-Mobility parts of the survey. Lower self-selected speed and asymmetrical walking compared to non-amputees indicated that amputee participants had lower levels of function. Results of the ABC scale questionnaire showed that most of them had moderate functional level (three amputees with good and one with a low level of functionality). These results corresponded with their PEQ-M scores. The kinematic and kinetic results of walking showed asymmetrical performance of amputees’ limbs with a prominent role of the intact limb. However, the relationship between the centre of mass (COM) and centre of pressure (COP) with lateral borders of BOS as the balance did not exhibit any difference between amputees and non-amputees, which shows proper balance maintenance of amputees during walking. For studying the biomechanics of standing balance, a perturbation was applied by a front/back-pulling load (2.5% of body weight) to the waist of each participant which, upon release, respectively induced backwards and forward falling. The observed changes in COP, COM, ground reaction forces and joint moments during standing and in response to the perturbation indicated that the intact limb of TF amputees had the main role in their balance, which resulted in an asymmetrical posture. Both groups used ankle movements to maintain balance in reaction to the perturbation.
Insoles use was associated with changes in a very limited number of biomechanical variables for non-amputees and in none of the amputees’ biomechanical variables. But, the quantitative evaluation of insoles showed most participants were satisfied with insoles and felt more comfortable in their daily activity during their use.
The results of this research (including both survey and biomechanical studies) affirm the necessity of providing more support (in the form of medical and musculoskeletal rehabilitation interventions) for LLAs to address the current issues, particularly with balance and their function in daily activities. The use of insoles in the initial phase of gait training after the first prosthesis fit might be beneficial for LLAs
