This work is supported by European Union Funds (FEDER/COMPETE - Operational Competitiveness Programme) and by national funds (FCT - Portuguese Foundation for Science and Technology) under the project FCOMP-01-0124-FEDER-022696.

TEMPORAL PARAMETERS OF THE FOOT ROLL-OVER DURING WALKING: WITH AND WITHOUT DIRECTION CHANGES IN

POSTMENOPAUSAL WOMEN

David Silva(1), Ronaldo Gabriel(2), Maria Moreira(3), João Abrantes(4), Aurélio Faria(5)

1. Departamento de Ciências do Desporto, Exercício e Saúde, UTAD, Portugal; 2. Departamento de Ciências do Desporto, Exercício e Saúde, CITAB, UTAD, Portugal; 3. Departamento de Ciências do Desporto, Exercício e Saúde, CIDESD, UTAD, Portugal; 4. MovLab, CICANT, Universidade Lusófona de Humanidades e Tecnologias, Portugal;

5. Departamento de Ciências do Desporto, CIDESD, UBI

Introduction Plantar pressure measurements can provide

important information about the various structures

of the foot during foot-ground interaction. Within

this context a reference dataset for temporal

characteristics of foot roll-over during jogging has

been established [De Cock, 2005] for young adults

and during walking [Monteiro, 2010] on

postmenopausal women (PW). In the last quoted

study the plantar pressure parameters were analysed

during straightforward walking however, there are

many changes of direction when regarding daily

activities. These changes in direction can induce

important modifications in the foot behaviour.

Therefore, the aim of this study was to compare, in

a group of PW, the temporal characteristics of foot

roll-over between the following tasks: (T1) walking

straightforward; and (T2) walking forward with

side-cut at 45º.

Methods Thirty-two PW participated in this study. Plantar

pressure parameters were evaluated by the Footscan

platform (RSscan, Olen, Belgium) at 250 Hz using

the two-step protocol [Bus & Lange, 2005].

Barefoot plantar pressure (right foot) data were

gathered during the both tasks, T1 and T2. The

initial contact time (IC), final contact time (FC) and

duration of contact (DC) was obtained for 10

anatomical pressure areas during foot roll-over. The

areas considered were: medial and lateral heel (HM,

HL), metatarsal areas (M1–M5), midfoot (MF),

hallux (H1) and toes (T2–5). Five instants of foot

roll-over were determined [Willems et al, 2006]

and based on these instants four phases were

established as illustrated in figure 1.

Figure 1: Instants and phases of foot rollover

Results

The IC (regions: toe 2-5, M5 and MF) and the FC

(regions: M3, M4 and M5) occurred significantly

earlier in task 2. The DC of T2-5 was significantly

greater in task 2 as the duration of the FFPOP phase

(Table1). The results also show, that the sequence

in which different foot areas touch the ground

diverges between both tasks: task 1; HL, HM, MF,

M3, M4, M2, M5,M1, H1, T2-5 and task 2; HL,

HM, MF, M4, M3, M5, M2, M1, T2-5, H1.

Table 1: Plantar pressure parameters

Variables T1 T2 Mann-Whitney

IC T2-5 57,6 ± 10,2 46,7 ± 14 P < 0.01

IC M5 22,9 ± 10,3 18,2 ± 12 P < 0.01

IC MD 8,3 ± 3,1 4 ±1,8 P < 0.01

FC M3 94,8 ± 1,4 93,4 ± 1,6 P < 0.01

FC M4 92,5 ± 1,6 90,2 ± 2 P < 0.01

FC M5 84,3 ± 4,8 82 ± 4,7 P < 0.01

DC T2-5 38,8 ± 10,5 48,9 ± 14,3 P < 0.01

FFPOP 42,4 ± 6,8 42,8 ± 8,6 P < 0.01

Task1-(T1); Task2- (T2); Values are mean ± SD

Discussion

Significant differences were found between tasks

for the IC, FC and DC. Houck et al. [Houck, 2006],

reported that during side-cut activities subjects tend

to initiate CoM movement toward the stance foot

and carried out the turn after complete the weight

acceptance. This data seems to support the increase

in duration that we found for the toe 2-5 and

FFPOP phase. The differences of the FC in M3,

M4, M5, could be explained by the inward foot

rotation during side-cut task which tend to induce

the most lateral metatarsals to lose contact earlier.

References

Bus & Lange, Clinical Biomech, 20:892-899, 2005.

De Cock, et al, Gait & Posture, 21: 432–439, 2005.

Faria, et al, Clinical Biomech, 25: 588-593, 2010.

Houck, et al, Gait & Posture, 24: 314-322, 2006.

Monteiro, et al, Maturitas, 67: 178-185, 2010.

Willems, et al, Gait & Posture, 23: 91-98, 2006.

Presentation 1428 − Topic 20. Gait and posture S235

ESB2012: 18th Congress of the European Society of Biomechanics Journal of Biomechanics 45(S1)