Effects of custom‐made textile insoles on plantar pressure distribution and lower limb EMG activity during turning

Abstract

BackgroundTurning during locomotion involves considerable changes of the body’s center of mass and reduced stability, as well as lower limb kinematics and kinetics. However, many previous studies have been carried out to evaluate the effectiveness and applications of orthotic insoles as well as different types of orthotic materials in various clinical symptoms, which are focused primarily on straight line walking. Hence, the influence of custom-made insoles with the use of advanced three-dimensional spacer fabrics on biomechanics parameters in terms of plantar pressure distribution and lower limb electromyography during turning movement was studied.MethodsTwelve subjects performed 180-degree turning at a speed 3.07-3.74 km/h for five successful trials under 3 insoles conditions: wearing traditional ethylene vinyl acetate insoles and two different spacer-fabricated insoles, with the plantar pressure and lower limb muscle activity collected simultaneously. Turning movement was broken down into 3 phases for analysis: Turning initiation, turn around and turn termination.ResultsThere was a statistically significance difference in plantar pressure between the traditional insoles and the insoles made of a spacer fabric as the top layer (p < 0.05). Compared to the traditional insoles, insoles made of a spacer fabric reduced the peak pressure (>12 %) and pressure–time integral (>13 %) in toes, metatarsal head 1 and metatarsal heads 2–3 at turning initiation; (>15 %) and (>17 %) in medial midfoot and medial heel at turn around. Insoles with spacer fabrics on the top and middle layer reduced both pressure parameters (>18 %) in toes and MTH 1 at turn termination. In terms of muscle activities, insoles with two-layer spacer fabrics could lower maximum muscle activities of vastus lateralis (>16 %; p < 0.05) at turn around.ConclusionsInsoles with different fabrications could offer various pressure offloading patterns across the plantar and muscle activity changes while turning. Insoles with a spacer fabric on the top tend to reduce plantar pressure loading at different regions during turn initiation and turn around phases, while two-layer spacer-fabricated insoles may contribute to reduced vastus lateralis muscle activation during turn around. More importantly, this study provides a new dimension in the potential use of the textile-fabricated insoles which may widen the range of insole materials selection in the design and development of insoles so as to enhance the effectiveness of orthotic treatment.

Material Selection for Diabetic Custom Insoles: A Systematic Review of Insole Materials and Their Properties

“…29,39 Two studies demonstrated better effect on shear forces by modifying the design of multilaminar insoles. 37,44 One study demonstrated that shear forces were highly correlated to the friction coefficient of the material and that lower-density materials had higher water vapor permeability. 24…”

“…Three studies reported the effect of insole thickness on offloading properties. 10,27,28 Nineteen clinical studies on material parameters were identified (see Table 3 8,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] ). Seventeen of these studies had plantar pressure/force measurements as the main outcome, but two studies also included shear forces, 30,37 and two studies had wound healing/prevention as outcome.…”

The biomechanical effects and perceived comfort of textile-fabricated insoles during straight line walking

“…Unlike walking in a straight line, the inner and outer limbs contribute in different ways to maintain stability during turning gait. Since the inner limbs have a crucial role on kinematic changes during the turning gait, there is a significant difference detected in the vastus lateralis muscle among the three types of insoles when the subject was turning in an earlier study carried out by Lo et al 42 Clearly, there is a need for further research on the efficacy of insole material combinations to determine whether they could produce consistent changes in muscle activity.…”

Reducing foot plantar pressure using superelastic nitinol monofilaments as spacer yarns in a novel weft knitted spacer fabric insole

“…Lo et al 17 performed an extensive experimental study on three samples of insoles which two of them were taking advantage of spacer fabrics in their structure. The first sample was made of EVA in the top, middle and bottom layer whereas the structure for insole 2 and 3 was polyester spacer fabric-polyurethane-EVA and polyester spacer fabric-polyester spacer fabric-EVA respectively.…”