Bodyweight distribution between limbs, muscle strength, and proprioception in traumatic transtibial amputees: a cross-sectional study

OBJECTIVES: To evaluate how transtibial amputation (TT) affects bodyweight distribution, voluntary knee joint position sense (JPS), and quadriceps (QUA) and hamstrings (HAM) strength in prosthetized patients. METHODS: Only TT patients who had been prosthetized for more than one year were included, and an age-paired able-bodied group was used as control. The participants stood on force plates with their eyes open to measure bodyweight distribution between the limbs. Knee voluntary JPS was assessed by actively reproducing a set of given arbitrary joint angles using a video analysis approach, and QUA and HAM strength were assessed isometrically with a hand-held dynamometer. RESULTS: Sixteen TT subjects (age: 39.4±4.8 years) and sixteen age-paired control subjects (age: 38.4±4.3 years) participated in the study. The amputees supported their bodyweight majorly on the sound limb (54.8±8.3%, p<0.001). The proprioceptive performance was similar between the amputated (absolute error (AE): 2.2±1.6°, variable error (VE): 1.9±1.6°, constant error (CE): -0.7±2.0°) and non-amputated limbs (AE: 2.6±0.9°, VE: 2.1±0.9°, CE: 0.02±2.3°), and was not different from that of control subjects (AE: 2.0±0.9°, VE: 1.4±0.4°, CE: -1.1±1.7°). There was a considerable weakness of the QUA and HAM in the amputated limb compared with the sound limb and control subjects (p<0.001 both). CONCLUSIONS: The asymmetric bodyweight distribution in the transtibial amputees was not accompanied by a reduction in knee proprioception. There was significant weakness in the amputated limb, which could be a potential issue when designing rehabilitation programs.

Senso de posição articular, força e distribuição de carga entre os membros inferiores em amputação transtibial-estudo transversal / Assessment of Sense of joint position, strength and load distribution among lower limbs in amputated patients at transtibial level

A amputação é definida como a retirada, geralmente cirúrgica, total ou parcial de um membro do corpo. As amputações traumáticas correspondem a aproximadamente 20% das amputações de membros inferiores não eletivas, sendo a amputação no nível transtibial o tipo mais frequente. Estudos anteriores já demonstraram alterações na sensibilidade do coto de amputação e quadro de hipotrofia muscular causada pelo desuso, tendo como principal consequência a deficiência de força. Diante disso, é importante identificar a influência da amputação na propriocepção, força e distribuição de carga entre os membros de pacientes com amputação transtibial de etiologia traumática. Objetivo: Avaliar alterações na distribuição de carga, propriocepção e capacidade de produção de força muscular dos músculos do joelho em indivíduos usuários de prótese devido à amputação no nível transtibial de origem traumática. Métodos: Estudo transversal no qual participaram 16 voluntários amputados, protetizados há mais de um ano e 16 indivíduos não amputados, que compuseram o grupo-controle. Os grupos foram avaliados através dos questionários de Perfil de Atividade Humana e Escala de Tegner para avaliar o perfil de atividade física. Os pacientes foram também avaliados em relação à distribuição de carga entre os membros, propriocepção, através do senso de posição articular, e força isométrica, na flexão e extensão dos joelhos. Resultados: Este estudo demonstrou que o grupo de pacientes amputados apresenta maior debilidade física. Observou-se que o membro amputado recebe menos peso corporal, não possui deficiência na propriocepção e apresenta força da musculatura isquiotibial maior quando comparados com os demais grupos. Conclusão: A amputação não provoca deficiência na propriocepção, mas acarreta um quadro de limitação física. Apesar disso, os músculos isquiotibiais apresentam mais força quando comparados com os demais grupos avaliados, o que torna interessante o desenvolvimento de mais estudos sobre a influência da amputação na biomecânica do ser humano

Amputation is generally defined as the surgical, total or partial removal of a body member. Traumatic amputations account for about 20% of non-elective lower limb amputations, with amputation at the transtibial level being the most frequent type. Previous studies have already shown changes in sensitivity of the amputation stump and muscle hypotrophy caused by disuse, with the main consequence being the strength deficit. Therefore, it is important to gain further insight into influence of amputation on proprioception, strength and load distribution among members of the transtibial amputee of traumatic etiology. Objective: To evaluate changes in load distribution, proprioception and muscle strength production capacity of knee muscles in prosthesis users due to amputation at transtibial level of traumatic origin. Methods: The study included 16 amputee volunteers who had been prosthetized for more than one year, and 16 non-amputees, who comprised the control group. The groups were submitted to the Human Activity Profile (HAP) and Tegner Scale questionnaires to assess their physical activity profile in addition to tests who evaluated load distribution, proprioception, through the sense of articular position, and isometric force, in flexion and knee extension. Results: Our study showed that the amputee group is physically impaired. We also noted that amputated limb receives less body weight, has no proprioceptive deficit, and has greater hamstring muscle strength when compared to other groups. Conclusion: Amputation does not cause proprioceptive deficit but causes physical limitation. Nevertheless, the hamstring muscles are stronger when compared to the other groups evaluated which makes interesting the development of further studies on the influence of amputation on human physiology