Moving from laboratory to real life conditions: influence on the assessment of variability and stability of gait

Researchers from MultiSim have been involved in a collaborative study about measuring gait analysis outside laboratory conditions. This collaboration was a result of the European Society of Biomechanics 2016 mobility award for young researchers awarded to Paola Tamburini.

Gait analysis (i.e. measuring how someone walks) can be a handy tool to assess how well someone walks and if walking is impaired e.g. as a result of diseases which impact movement quality. Previously, conducting gait analysis required expensive equipment and trained specialists, and to bring the person being observed to a clinic or a laboratory. However, walking in a clinic/laboratory probably isn’t the best replication of walking in a free-living environment without observation. Thanks to technological advancements we now have devices which can measure movement (inertial measurement units) and have both an adequate battery life and are physically small enough to unobtrusively measure people’s movements from different locations of the body. They also do not require a clinic/laboratory. These small devices continuously measure movement many times per second, and as a result, new ways of measuring movement quality have been created.

The two types of new measures that exist are variability of gait and stability of gait. At present, it is not known whether variables useful when measured in a clinic/laboratory change when measured in a free-living environment or vice versa. This experiment tested whether healthy and young individuals’ gait changed when tested in different environments. It was predicted that their gait variability would change but their stability would not.

To test this theory, 19 participants were measured walking in four different environments. One to replicate gait analysis in a laboratory/clinic and another to do the same but outdoors and over a longer distance. In the two other conditions tested, the participant was free to walk wherever they liked in: an urban environment (city centre) and corridors of a large university building. For last two environments, the participant would have to avoid obstacles such as pedestrians, whereas, for the first two environments, the examiners ensured their walking would not be disturbed.

Results showed that the prediction was correct whereby the gait stability did not change between environments but gait variability did. As a result, if using these gait variability measures to assess how well someone is walking, the environment in which the walking was tested should be considered when interpreting the results. Whereas for gait stability measures, which are proposed to be better indicative of motor control, when making comparisons for healthy participants, the environment does not need to be considered. Future work is required to see if these results are reflected in groups where gait is expected to be impaired.

This study provides evidence that it may be possible to measure gait stability in all environments and consequently this method of gait analysis may be used to measure gait without the need of a visit to a clinic or laboratory. This makes this new approach have cost and logistical advantages over our current approach.

 

Publishes in Gait and Posture 2018

Full Text: https://doi.org/10.1016/j.gaitpost.2017.10.024