Static Standing Trunk Sway Assessment in Amputees – Effects of Sub‐Threshold Stimulation

Abstract

Sub‐threshold electrical stimulation can enhance the sensitivity of the human somatosensory system to improve the balance control capability of elderly was shown in recent rehabilitation articles. The purpose of this study was to evaluate the postural sway of trans‐tibial amputees when performing single leg quiet standing on firm surface. Four unilateral trans‐tibial amputees who consecutively wore prosthetics over 2 years were recruited in this study. Subjects performed single leg quiet standing trails with sub‐threshold electrical stimulation applied at the quadriceps muscle during the trails. Spatial co‐ordinates for the determination kinematic data (sway distance) of the center of mass (COM) on second sacral (S2) were collected using an ultrasound‐based Zebris CMS‐HS system. The single leg quiet standing test is measure considered to assess postural steadiness in a static position by a spatial measurement. The common notion is that a better postural steadiness, i.e. less postural sway, allows for longer time single leg quiet standing. However, there is lack of evidence how postural steadiness during single leg quiet standing changes over time. In this article, we hypothesized that the static balance of single leg quiet standing could be improved for providing proprioceptive neuromuscular facilitation using sub‐sensory stimulation in amputees. To test this hypothesis, a computerized sub‐threshold low‐level electrical stimulation device was developed and proposed for clinical study. Experimental results show that reduction in all of the postural sway indices (constant time sway length, max sway distance and average sway distance) and increase in single leg support time index during single leg quiet standing by applying sub‐sensory stimulation. The single leg quiet standing test findings suggest that sub‐threshold electrical stimulation rehabilitation strategies may be effective in improving static balance performance for amputees.

Quantitative methods used to evaluate balance, postural control, and the fear of falling in lower limb prosthesis users: A systematic review

“…The results from the current study showed a large bias toward recruiting males in research in this area. The reported 26.4% of female lower limb prosthesis users participating in studies was lower than what has been reported in a highly regarded national amputation registry (SwedeAmp; 39%), 234 as well as in previous research (34.5%–38.4%) such as Claessen et al 235 and Ziegler-Graham et al 236 The present authors think it is noteworthy that, of the (n = 161) articles reporting characteristics on sex in the balance articles in Supplemental Table (Supplemental Digital Content 2, http://links.lww.com/POI/A170) 12-14,19-23,25,26,28,29,31-42,44,45,47,48,50-56,58,59,62-69,71-75,77-85,88-90,92,94-102,105-120,122-136,138,140-153,155,157-165,167-179,181-184,186-198,230,231 and the (n = 62) articles of balance confidence, 4,6,8,14,44,71,78,81,83,94,134,138,143,145,147,148,150,151,153,155,157,159,163,165,172,175-178,183,193,196,199-203,205-209,211-229 29.2% and 19.4% respectively, included male sex exclusively. There were only (n = 2) studies with female participants, one balance article 231 and one balance confidence article.…”

“…13,71-107 Less common were single-limb measurements. 79,92,94,108-113 The equipment used across studies varied, but the most common was multiple force plates (Figure 2). 12,19-48,51-60,62-70,114-117 Motion capture systems were also common.…”

“…13,71-108,110 Some few studies used plantar force sensor insoles, 50,112-114,139 inertial or accelerometer sensors, 95,140-142 instrumented mat or walkway, 117,124,143 or a plantar pressure platform (Figure 2). 49,61,111,144-146…”

“…13, Less common were single-limb measurements. 79,92,94,[108][109][110][111][112][113] The equipment used across studies varied, but the most common was multiple force plates (Figure 2). 12,[51][52][53][54][55][56][57][58][59][60][62][63][64][65][66][67][68][69][70][114][115][116][117] Motion capture systems were also common.…”

“…13,110 Some few studies used plantar force sensor insoles, 50,[112][113][114]139 inertial or accelerometer sensors, 95,[140][141][142] instrumented mat or walkway, 117,124,143 or a plantar pressure platform (Figure 2). 49,61,111,[144][145][146] Looking at the protocols and tests, the most commonly found was the Berg Balance Scale, or selected items of the Berg Balance Scale (Figure 2). 14,31,73,[80][81][82]93,94,103,107,[118][119][120][138][139][140]144, Timed Up and Go 76,107,117,144,145,148,149,151,162,163,…”