Foot Clearance

  • Contact person: Anisoara Ionescu
  • People involved: Benoît Mariani
  • Partners: CHUV – IUMSP
  • Funding source:


One third of community-dwelling people older than 65 years fall each year. Falls have many adverse consequences in older people, including major injuries, functional decline, activity restriction and reduced quality of life. Foot clearance, defined as the foot’s height during the swing phase, seems an important gait parameter that should be related to the risk of falling. Contrary to other gait parameters, there is an unambiguous mechanism that links impaired foot clearance to falls. During walking, insufficient or fluctuations in foot clearance could lead directly to tripping, a major cause of fall in older people. Surprisingly, despite this intuitive relationship, only few studies investigated so far the characteristics of foot clearance pattern, and only in small selected study sample.

Therefore, several major gaps remain in our knowledge about the clinical significance of foot clearance in older persons. This study aims to investigate foot clearance pattern and contribute to improving our understanding of its potential association with different important factors related to falls in older people.


In this study we will use data from nearly 1000 participants aged 71 to 75 years included in the “Lc65+” cohort, that enrolled a representative sample of community-dwelling people in the city of Lausanne area.

An assessment of spatio-temporal gait parameters will be conducted under single and dual task conditions, using a portable gait analysis system directly worn on the shoes of the participants. Several features of foot clearance pattern will be evaluated, including minimum and maximum toe clearance (minimal and maximal distance between toes and ground during the swing phase, respectively), heel clearance and variability of these parameters. New analytical methods to characterize 3D foot trajectory will be developed.

Expected value

This is the first large study to investigate foot clearance in a sample of representative community-dwelling elderly people. Benefits from the project are expected in several areas.

First, this project will bring valuable new information on foot clearance pattern, including 3D trajectory of the foot, foot orientation and elevation during swing phases. Methods to analyze foot clearance pattern that will be developed will provide new insights into gait kinematics. Results will help to determine the most sensitive and specific way to analyze this parameter in the prediction of falls.

Second, the results of this project will also help to better understand the complex relationship between gait performance and falls in elderly people, and to determine the potential role of foot clearance in this relationship.

Third, the information gathered in this study will increase our knowledge on the relationship between fear of falling and gait performance. This will be the first study to determine whether an independent association between fear of falling and foot clearance is observed.

Finally, this study will allow describing the effect of dual tasking on foot clearance. It is currently unclear whether foot clearance will be affected or not by attention demanding task. If confirmed, this finding will extend our understanding of the cognitive control of gait. It will also have potential implications for future research to determine age-related or frailty-related changes in this relationship, as well as for rehabilitation.

Main publications

Journal Papers

Mariani, B., Hoskovec, C., Rochat, S., Büla, C., Penders, J., Aminian, K. 3D gait assessment in young and elderly subjects using foot-worn inertial sensors. Journal of Biomechanics – 16 November 2010 (Vol. 43, Issue 15, Pages 2999-3006, DOI: 10.1016/j.jbiomech.2010.07.003)


Mariani, B., Aminian, K. 3D Gait Analysis using wearable 6D IMU on shoe. In Proceedings of the XIX Conference of the International Society for Posture & Gait Research, Bologna, Italy, 2009, 47-48.

Aminian, K., Mariani, B., Hoskovec, C., Rochat, S., Büla, C., Penders, J. 3D Gait assessment using wearable inertial sensors: walking performance in young and elderly subjects. In Proceedings of the 11th International Symposium on the 3D Analysis of Human Movement, San Francisco, USA, 2010.

Mariani, B., Rochat, S., Hoskovec, C., Büla, C., Santos-Eggiman, B., Aminian, K. Estimation of heel & toe clearance during gait using foot-worn sensors: application to dual-task studies in elderly persons. In Proceedings of the International Conference on Ambulatory Monitoring of Physical Activity and Movement, Glasgow, Scotland, 2011.