Evaluation of an adjustable ankle-foot orthosis impact on walking stability during gait transitional phases

Gait dynamic stability evaluation in patients undergoing hip joint fractures – tools to measure rehabilitation effectiveness

“…The CoP waveforms have been used earlier to evaluate gait stability during weight-loading and unloading transitions [9,14,27]. Following that, the CoP raw data was extracted from the GaitRec repository both in anterior-posterior (AP) and medial-lateral (ML) directions.…”

“…A lower-order filter was selected to avoid unnecessary time delays and over-smoothening that can diminish the difference between fractured and normal waveforms. Similar filter specs were also used earlier for cleaning CoP-velocity signals [14,27,32]. The rate-of-change (derivative) of CoP signals was computed and thereafter averaging algorithm was applied to reduce the derivative-induced noise following prior studies [9,14,27].…”

“…Earlier, it has been reported that walking stability is difficult to maintain during interlimb weight shifting in patients undergoing lower limb impairments [12]. This is also because maximum neuromuscular activities take place in the lower-limb muscles during these periods [13,14] and the deficiency of weight bearing by the fractured limb resulted in the interruption of proprioception feedback which is required by the neuromotor to execute the normal gait dynamics [10,15,16]. Patients with hip joint fractures have initially limited weight-bearing capacity due to pain in the affected limb, poor blood circulation, bone alignment, healing of soft tissues, and risk of re-injury [5,17,18].…”

“…Gait dynamic stability assessment methods are broadly categorised into three ways: (1) the Lyapunov exponent [19,20] and variability analysis [21,22] methods use whole gait cycle data to compute the stability metrics; (2) the margin of stability computes body's centre of mass (CoM) difference from the base of support at discrete gait events (heel contact and toeoff) [21,[23][24][25]; (3) Nyquist and Bode (N&B) methods compute critical stability margins within a sub-phase of a gait cycle [9,14,[26][27][28][29]. Among these reported techniques, stability assessment using whole gait cycle waveforms or at discrete gait events has obvious limitations of stability evaluation during gait inner phases such as weight loading and unloading.…”

“…The third approach (N&B) is the most recent one that has been reported with the advantage of evaluating stability during gait loading and unloading phases using a single centre of pressure (CoP) signal. The CoP was reported as the resultant neuromotor-generated response in the presence of the body's internal/ external disturbances [14,21] and has been used as a measure of postural recovery in fracture-healing patients [4,30]. Therefore, considering the methodological choices, the N&B methods are potential choices to measure gait stability in the gait inner phases in patients undergoing hip joint fractures.…”