Walking on uneven terrain in healthy adults and the implications for people after stroke

Abstract

BACKGROUND One third of individuals after stroke report an inability to walk in the community. Community mobility requires walking adaptability—the ability to adjust one’s stepping pattern to meet environmental demands and task goals. Walking on uneven terrain (e.g. grass, gravel) has unique requirements and is a critical component of walking adaptability that has not been investigated in the post-stroke population. OBJECTIVE To summarize current knowledge of biomechanical and neuromuscular modifications during uneven terrain negotiation in healthy individuals and discuss implications of post-stroke impairments. METHODS Review of eleven studies, identified through a search of relevant literature on PubMed and CINAHL. RESULTS On uneven terrain, healthy adults demonstrate numerous gait modifications including a lowered center of mass, increased muscle co-contraction during stance and exaggerated or increased toe clearance during swing. After stroke, changes in muscle activity and limb coordination will likely result in difficulty or inability performing these modifications that healthy adults use to maintain stability and safety when walking on uneven terrain. CONCLUSIONS Studies of biomechanical and neuromuscular control of walking on uneven terrain are needed to quantify mobility limitations in adults post-stroke. Such investigations will contribute to the understanding of mobility impairments after stroke and the design of critically important intervention strategies.

Assessment of backward walking unmasks mobility impairments in post-stroke community ambulators

“…6 Given the mobility challenges experienced by adults post-stroke, greater attention to walking adaptability is warranted. 4,7 Backward walking (BW) is a walking adaptation that has received little attention until recently in the post-stroke literature. [8][9][10][11][12] While continuous BW may rarely be needed, BW for short distances is critical for safe negotiation of tight spaces or a crowded room, when opening a door, or when backing up to sit down.…”

Models for temporal-spatial parameters in walking with cadence ratio as the independent variable

“…Accurate temporal-spatial models have always been desirable in the biomechanical field [ 21 – 28 ]. However, it can be difficult to obtain correct mathematical models because the temporal-spatial parameters are easily influenced by factors such as age [ 42 ], floor conditions [ 43 , 44 ], and subjective attention [ 45 ]. Therefore, simple empirical models are often used instead [ 1 , 26 , 28 , 37 , 38 ]; these describe the gait parameters within a certain speed range with a certain accuracy.…”

Rough substrates constrain walking speed in ants through modulation of stride frequency and not stride length

“…Surprisingly, the dependence of speed on stride frequency and not stride length was retained for walking on uneven ground in ants. When confronted with uneven terrain, humans generally reduce step lengths [38,39], particularly in older adults or in individuals with compromised gaits who must compensate for reduced balance [40,41]. Although ants slowed down on rough substrates, these speed reductions were primarily modulated by changes in stride frequency.…”