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The generation of centripetal force when walking in a circle: insight from the distribution of ground reaction forces recorded by plantar insoles.

Turcato AM, Godi M, Giordano A, Schieppati M, Nardone A - J Neuroeng Rehabil (2015)

Bottom Line: During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot.On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot.At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In.

View Article: PubMed Central - PubMed

Affiliation: Posture and Movement Laboratory, Division of Physical Medicine and Rehabilitation, Scientific Institute of Veruno, Fondazione Salvatore Maugeri (IRCCS), Veruno, NO, Italy. turcato.anna@gmail.com.

ABSTRACT

Background: Turning involves complex reorientation of the body and is accompanied by asymmetric motion of the lower limbs. We investigated the distribution of the forces under the two feet, and its relation to the trajectory features and body medio-lateral displacement during curved walking.

Methods: Twenty-six healthy young participants walked under three different randomized conditions: in a straight line (LIN), in a circular clockwise path and in a circular counter-clockwise path. Both feet were instrumented with Pedar-X insoles. An accelerometer was fixed to the trunk to measure the medio-lateral inclination of the body. We analyzed walking speed, stance duration as a percent of gait cycle (%GC), the vertical component of the ground reaction force (vGRF) of both feet during the entire stance, and trunk inclination.

Results: Gait speed was faster during LIN than curved walking, but not affected by the direction of the curved trajectory. Trunk inclination was negligible during LIN, while the trunk was inclined toward the center of the path during curved trajectories. Stance duration of LIN foot and foot inside the curved trajectory (Foot-In) was longer than for foot outside the trajectory (Foot-Out). vGRF at heel strike was larger in LIN than in curved walking. At mid-stance, vGRF for both Foot-In and Foot-Out was higher than for LIN foot. At toe off, vGRF for both Foot-In and Foot-Out was lower than for LIN foot; in addition, Foot-In had lower vGRF than Foot-Out. During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot. On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot. At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In.

Conclusions: The lower gait speed during curved walking is shaped by the control of trunk inclination and the production of asymmetric loading of heel and metatarsal heads, hence by the different contribution of the feet in producing the body inclination towards the centre of the trajectory.

No MeSH data available.


Asymmetry index (AI) of the estimated ground reaction force distribution at the heel, metatarsal heads, arches and toes of the foot during linear (LIN) and curved trajectories (Foot-In, Foot-Out). In the ordinate, larger negative values (average ± standard error, SE) of AI represent an increase in vGRF on the lateral part of the relevant foot region. During curved walking, AI of the Foot-Out heel became more negative than that of LIN foot and Foot-In. On the contrary, AI became less negative for Foot-In with respect to LIN foot. At the metatarsal heads, AI showed the opposite behaviour: for Foot-Out, it became slightly less negative with respect to LIN foot. On the contrary, for Foot-In, it became more negative than LIN foot and Foot-Out. *, p < 0.05; **, p < 0.005; ***, p < 0.0005.
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Fig4: Asymmetry index (AI) of the estimated ground reaction force distribution at the heel, metatarsal heads, arches and toes of the foot during linear (LIN) and curved trajectories (Foot-In, Foot-Out). In the ordinate, larger negative values (average ± standard error, SE) of AI represent an increase in vGRF on the lateral part of the relevant foot region. During curved walking, AI of the Foot-Out heel became more negative than that of LIN foot and Foot-In. On the contrary, AI became less negative for Foot-In with respect to LIN foot. At the metatarsal heads, AI showed the opposite behaviour: for Foot-Out, it became slightly less negative with respect to LIN foot. On the contrary, for Foot-In, it became more negative than LIN foot and Foot-Out. *, p < 0.05; **, p < 0.005; ***, p < 0.0005.

Mentions: Figure 4 shows that AI was negative for both linear and curved trajectories in the cases of the heel, arch and metatarsal heads, in keeping with the larger vGRF on the lateral than medial part of these foot regions. AI of the forefoot at the toes was positive, again regardless of the trajectory, indicating a larger vGRF on the hallux than lateral toes. Turning trajectory significantly modulated AI of the heel and the metatarsal heads, not so AI of the arch and toes. During LIN trajectory, AI of both heel and metatarsal heads showed an intermediate value between those for CW and CCW. One-way ANOVA showed a significant effect of feet (LIN foot, Foot-In, Foot-Out) on the heel (F(2,96) = 26.31; p < 0.0001), metatarsal heads (F(2,96) = 3.57; p < 0.05), but not on the arches (F(2,96) = 0.75; p = 0.47) and toes (F(2,96) = 0.37; p = 0.69). The post-hoc test showed that, during curved walking, AI of the Foot-Out heel became more negative than that of LIN foot (p < 0.0005) or Foot-In (p < 0.0005). This was in keeping with an increasing greater loading of the lateral part of the heel for Foot-Out with respect to Foot-In and LIN foot. On the contrary, AI became less negative for Foot-In with respect to LIN foot (p < 0.01), sign of a decreasing lateral loading of the heel. At the metatarsal heads, AI acted in the opposite way: for Foot-Out, it became slightly less negative (p = 0.62) with respect to LIN foot while, for Foot-In, it became more negative than LIN foot (p = 0.21) and Foot-Out (p < 0.05), in keeping with an increasing larger loading of the lateral part of the metatarsal heads of Foot-In with respect to Foot-Out and LIN foot.Figure 4


The generation of centripetal force when walking in a circle: insight from the distribution of ground reaction forces recorded by plantar insoles.

Turcato AM, Godi M, Giordano A, Schieppati M, Nardone A - J Neuroeng Rehabil (2015)

Asymmetry index (AI) of the estimated ground reaction force distribution at the heel, metatarsal heads, arches and toes of the foot during linear (LIN) and curved trajectories (Foot-In, Foot-Out). In the ordinate, larger negative values (average ± standard error, SE) of AI represent an increase in vGRF on the lateral part of the relevant foot region. During curved walking, AI of the Foot-Out heel became more negative than that of LIN foot and Foot-In. On the contrary, AI became less negative for Foot-In with respect to LIN foot. At the metatarsal heads, AI showed the opposite behaviour: for Foot-Out, it became slightly less negative with respect to LIN foot. On the contrary, for Foot-In, it became more negative than LIN foot and Foot-Out. *, p < 0.05; **, p < 0.005; ***, p < 0.0005.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4325939&req=5

Fig4: Asymmetry index (AI) of the estimated ground reaction force distribution at the heel, metatarsal heads, arches and toes of the foot during linear (LIN) and curved trajectories (Foot-In, Foot-Out). In the ordinate, larger negative values (average ± standard error, SE) of AI represent an increase in vGRF on the lateral part of the relevant foot region. During curved walking, AI of the Foot-Out heel became more negative than that of LIN foot and Foot-In. On the contrary, AI became less negative for Foot-In with respect to LIN foot. At the metatarsal heads, AI showed the opposite behaviour: for Foot-Out, it became slightly less negative with respect to LIN foot. On the contrary, for Foot-In, it became more negative than LIN foot and Foot-Out. *, p < 0.05; **, p < 0.005; ***, p < 0.0005.
Mentions: Figure 4 shows that AI was negative for both linear and curved trajectories in the cases of the heel, arch and metatarsal heads, in keeping with the larger vGRF on the lateral than medial part of these foot regions. AI of the forefoot at the toes was positive, again regardless of the trajectory, indicating a larger vGRF on the hallux than lateral toes. Turning trajectory significantly modulated AI of the heel and the metatarsal heads, not so AI of the arch and toes. During LIN trajectory, AI of both heel and metatarsal heads showed an intermediate value between those for CW and CCW. One-way ANOVA showed a significant effect of feet (LIN foot, Foot-In, Foot-Out) on the heel (F(2,96) = 26.31; p < 0.0001), metatarsal heads (F(2,96) = 3.57; p < 0.05), but not on the arches (F(2,96) = 0.75; p = 0.47) and toes (F(2,96) = 0.37; p = 0.69). The post-hoc test showed that, during curved walking, AI of the Foot-Out heel became more negative than that of LIN foot (p < 0.0005) or Foot-In (p < 0.0005). This was in keeping with an increasing greater loading of the lateral part of the heel for Foot-Out with respect to Foot-In and LIN foot. On the contrary, AI became less negative for Foot-In with respect to LIN foot (p < 0.01), sign of a decreasing lateral loading of the heel. At the metatarsal heads, AI acted in the opposite way: for Foot-Out, it became slightly less negative (p = 0.62) with respect to LIN foot while, for Foot-In, it became more negative than LIN foot (p = 0.21) and Foot-Out (p < 0.05), in keeping with an increasing larger loading of the lateral part of the metatarsal heads of Foot-In with respect to Foot-Out and LIN foot.Figure 4

Bottom Line: During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot.On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot.At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In.

View Article: PubMed Central - PubMed

Affiliation: Posture and Movement Laboratory, Division of Physical Medicine and Rehabilitation, Scientific Institute of Veruno, Fondazione Salvatore Maugeri (IRCCS), Veruno, NO, Italy. turcato.anna@gmail.com.

ABSTRACT

Background: Turning involves complex reorientation of the body and is accompanied by asymmetric motion of the lower limbs. We investigated the distribution of the forces under the two feet, and its relation to the trajectory features and body medio-lateral displacement during curved walking.

Methods: Twenty-six healthy young participants walked under three different randomized conditions: in a straight line (LIN), in a circular clockwise path and in a circular counter-clockwise path. Both feet were instrumented with Pedar-X insoles. An accelerometer was fixed to the trunk to measure the medio-lateral inclination of the body. We analyzed walking speed, stance duration as a percent of gait cycle (%GC), the vertical component of the ground reaction force (vGRF) of both feet during the entire stance, and trunk inclination.

Results: Gait speed was faster during LIN than curved walking, but not affected by the direction of the curved trajectory. Trunk inclination was negligible during LIN, while the trunk was inclined toward the center of the path during curved trajectories. Stance duration of LIN foot and foot inside the curved trajectory (Foot-In) was longer than for foot outside the trajectory (Foot-Out). vGRF at heel strike was larger in LIN than in curved walking. At mid-stance, vGRF for both Foot-In and Foot-Out was higher than for LIN foot. At toe off, vGRF for both Foot-In and Foot-Out was lower than for LIN foot; in addition, Foot-In had lower vGRF than Foot-Out. During curved walking, a greater loading of the lateral heel occurred for Foot-Out than Foot-In and LIN foot. On the contrary, a smaller lateral loading of the heel was found for Foot-In than LIN foot. At the metatarsal heads, an opposite behaviour was seen, since lateral loading decreased for Foot-Out and increased for Foot-In.

Conclusions: The lower gait speed during curved walking is shaped by the control of trunk inclination and the production of asymmetric loading of heel and metatarsal heads, hence by the different contribution of the feet in producing the body inclination towards the centre of the trajectory.

No MeSH data available.