Assessing preparative gait adaptations in persons with transtibial amputation in response to repeated medial-lateral perturbations

Abstract

Preventing loss of balance in individuals with transtibial amputation is important, as they are susceptible to a high frequency of fall related injuries. In order to validate fall prevention and balance therapies, methods to assess gait stability must be developed. Kinematic, temporal-spatial, and center of mass data from six healthy young participants with transtibial amputation were collected during treadmill walking during exposure to 10 randomly ordered discrete medial-lateral perturbations. The 20 strides prior to each perturbation were assessed for anticipatory changes. The only consistent postural adjustment made as a result of the perturbations was a significantly lowered center of mass height (p = 0.016).

Proactive Locomotor Adjustments Are Specific to Perturbation Uncertainty in Below-Knee Prosthesis Users

“…In anticipation of unknown time perturbations, BKPU participants did make small increases in step width and decreases in step time. Although small, these proactive modifications should theoretically enhance frontal-plane stability 5 , 33 , 38 and are consistent with previous research findings that individuals with below-knee amputation make only minimal proactive gait adaptations in response to repeated mediolateral perturbations 22 . However, the absence of clear proactive adaptations is inconsistent with findings that non-impaired populations make proactive modifications in preparation for destabilizing events that will occur at an unknown time 39 – 41 , and that BKPUs increase step width while walking with continuous perturbations 20 , 23 , or over unstable terrain 19 , 24 .…”

“…Curiously, BKPUs appear to make only small anticipatory gait adaptations when repeatedly exposed to discrete but temporally-unpredictable lateral perturbations 22 . This result is surprising considering that BKPUs are both fall prone 8 and able to adapt gait patterns to further increase frontal-plane stability as evidenced by their response to environments that continuously challenge mediolateral balance 15 , 20 , 23 , 24 .…”

“…Accordingly, when BKPUs anticipate a temporally-unpredictable perturbation with a known recoverable magnitude (i.e., below the threshold which would result in a fall) as employed in the study by Sturdy et al . 22 , choosing to maintain their preferred (already cautious) gait pattern would help avoid those costs associated with further proactive adaptations to increase stability. Consequently, the provision of spatiotemporal knowledge of a perturbation could in theory minimize the negative trade-offs associated with proactive gait stability strategies by encouraging context-specific adaptations.…”

Postural Sway and Motor Control in Trans-Tibial Amputees as Assessed by Electroencephalography during Eight Balance Training Tasks

“…Balance is an important part of rehabilitation [ 37 ] because falls are a major predisposing factor for fractures and death in the elderly [ 38 , 39 ]. It is well known that the loss of a foot or leg can reduce balance and impair gait [ 18 , 40 ]. This has the effect of increasing falls and reducing the quality of life [ 5 ].…”

Effect of real-time video feedback on the gait foot placement regularity and symmetry in individuals with trans-tibial amputation: A case study

“…This indicates that visual feedback from neither of directions could influence gait stability in ML direction. A recent study also reported minimal change in gait stability under perturbations induced in ML direction (Sturdy, Gatesa, Dartera, & Wilkena, 2014). In addition, the participants in our study walked on a motorized treadmill the width of which could restrict their step width adjustment ability.…”