Short communicationWearing the F-Scan mobile in-shoe pressure measurement system alters gait characteristics during running
Introduction
In-shoe pressure measurement systems are useful tools to obtain plantar pressure and force data during dynamic movements. Such systems are widely used in locomotion [1], sports [2] and footwear [3] research, and have led to success in clinical applications [4]. The repeatability [5], [6], [7], [8] and accuracy [5], [8], [9] of data measured using various commercial in-shoe pressure measurement systems have been addressed in the literature. Recording plantar pressure data using these systems requires external devices attached to the subjects. However, it has not been documented whether wearing these external devices will influence human movement. If these devices hinder natural movement patterns, data obtained while wearing these devices may not represent those during natural, unrestricted movements.
The F-Scan mobile system (Tekscan Inc., Boston, USA) is one of the most commonly used in-shoe pressure measurement system for gait analysis. This system utilized relatively low-cost and thin in-shoe sensors which can be easily trimmed to fit the size and shape of a shoe. Another advantage of this system is that pressure data are stored in a data-logger so that the subject can move freely and that field tests are made possible. However, this system has been criticized for its poor accuracy and repeatability [8]. While the F-Scan system is less superior in comparison to another commercial product – the Pedar system, its accuracy and precision can be greatly improved by using appropriate pressure for calibration [9].
The total mass of all external devices of the F-Scan system to be attached to the subject was approximately 1.8 kg, including two in-shoe sensors, two receiver units attached to the subject's lower leg, one data-logger unit attached at the waist level, several connecting cables and straps. Before using this system in running research, it was of interest to the investigators to examine the effect of wearing the F-Scan devices on the natural running pattern. It was believed that the F-Scan devices may affect running movement due to the following three reasons:
- (1)
Additional mass of the system
It is well addressed that shoes of heavier mass negatively affect running economy [10], [11]. An increase in mass attached to the foot has also been shown to cause a decrease in running economy and stride frequency [12]. Thus, it was believed that the additional mass of the F-Scan system, in particular the ankle unit, may alter normal running pattern.
- (2)
Reduced friction at the foot/shoe interface
The friction at the foot/shoe interface affects the shear force acting on the foot [13]. By altering sensory input at the plantar surface of the foot, one alters gait kinetics and muscular activation patterns [14]. The low friction of the F-Scan sensor may therefore lead to a change in gait characteristics.
- (3)
Obstruction from external units, cables and straps
The external devices may hinder natural arm-swing and leg-swing movements, causing runners to alter running style.
The purpose of the present study, therefore, was to compare the gait characteristics during running with and without wearing the F-Scan mobile in-shoe pressure measurement system.
Section snippets
Methods
Six elite male runners (age = 22.0 ± 1.8 y, mass = 63.0 ± 7.3 kg, height = 1.77 ± 0.06 m) participated in the study. These runners were collegiate athletes competing at the National Collegiate Athletic Association Division 1 level at the time of the study. All experimental procedures were approved by the Institutional Review Board and informed consents were obtained prior to data collection. In order to identify touchdown and toe-off, reflective markers were placed on the heel and second metatarsal head over
Results
Table 1 presents the stride frequency, stride length, relative stride length and stance time when running with and without wearing the F-Scan system at three different speeds. Wearing the F-Scan system did not affect the stance time but lead to an increase in stride frequency (P < 0.05) and a decrease in stride length (P < 0.05) and relative stride length (P < 0.05). Under both conditions as speed increased, stance time decreased while stride frequency, stride length and relative stride length
Discussion
This study demonstrates that running while wearing the F-Scan mobile in-shoe measurement system leads to a higher stride frequency and shorter stride length compared with normal running on a treadmill. These results support our hypothesis that wearing external devices can alter gait characteristics during running. This implies that plantar pressure, ground reaction force and centre of pressure data obtained from the F-Scan system may not represent those in a real life setting without the
Conflict of interest statement
No personal relationship or financial support from any organizations would inappropriately influence this study.
Acknowledgements
The authors would like to thank Jason van Haselen for his help in analyzing the gait data, Dr Stephen Burns and Dr Mansoo Ko for their contribution in revising this manuscript, and Frans de Heer and Frank Remkes for their support in the development phase of the project.
References (18)
- et al.
In-shoe pressure distribution in “unstable” (MBT) shoes and flat-bottomed training shoes: a comparative study
Gait Posture
(2007) - et al.
A comparison of vertical force and temporal parametesr produced by an in-shoe pressure measuring system and a force platform
Clin Biomech
(2001) - et al.
The Pedar in-shoe system: repeatability and normal pressure values
Gait Posture
(2007) - et al.
Observations on the F-Scan in-shoe pressure measuring system
Clin Biomech
(1997) - et al.
Effect of sock on biomechanical responses of foot during walking
Clin Biomech
(2006) - et al.
The effect of changes in foot sensation on plantar pressure and muscle activity
Clin Biomech
(2001) - et al.
A kinematic and kinetic comparison of overground and treadmill walking in healthy subjects
Gait Posture
(2007) - et al.
Gait and posture responses to backpack load during level walking in children
Gait Posture
(2003) - et al.
Walking and running plantar pressure analysis before and after resection of tarsal coalition
Foot Ankle Int
(2007)
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