Identification of individual walking patterns using time discrete and time continuous data sets
Introduction
During the 20th century, quantitative gait analysis has been developed and used to support clinicians’ and therapists’ decisions when assessing gait abnormalities and/or identifying changes due to orthopaedic or physiotherapeutic interventions. Typically, sets of time discrete variables have been used to predict prevention of injuries and/or assessment of rehabilitation procedures. Furthermore, artificial neural network applications have been developed for gait analysis to distinguish between healthy and pathological walking patterns [1], [2] using an external teacher to ‘train’ the networks.
Conventional gait analysis for clinical or general applications is associated with some inherent problems. First, conventional gait analysis uses typically time discrete variables. However, everyday experiences indicate that it is difficult to recognize a known person from a distance as long as he/she is standing. However, as soon as the person starts moving, the recognition is vastly improved, probably because the observer assesses the movement pattern of the observed person [3], [4]. In general, time discrete and time continuous data sets provide different information to the observer.
Second, conventional gait analysis reproduces only classifications or behaviours of groups that are expected by the gait analysists. Subjects are divided into normal and excessive pronators, for instance. However, groupings that are not pre-programmed by the project manager are typically not detected using this approach.
Third, conceptual differences between the scientific and the clinical approach influence conventional gait analysis. The scientific approach tends to be more group-oriented. The clinical approach tends to be more subject-oriented. However, the ability of recognizing and/or modifying subject specific movement patterns is of particular interest for successful and effective therapeutic interventions.
A novel approach of movement analysis using a time course oriented analysis with non-linear classifying self organized neural networks has been presented recently [5]. It addressed the outlined shortcomings of the conventional movement analysis and was able to identify individual movement patterns for various types of sports movements [6], [7]. Thus, it seems reasonable to assume that this movement analysis strategy could also be used in clinical situations where group and subject specific aspects are of importance.
Thus, the purposes of this study were
- 1.
to determine individual movement characteristics using time discrete data,
- 2.
to determine individual movement characteristics using time course oriented data,
- 3.
to identify groups with similar movement characteristics using the time discrete and time course oriented data and
- 4.
to compare the two approaches in their ability in identifying individual and/or group movement characteristics.
Section snippets
Data acquisition
The data collection for this study has been described in detail elsewhere [8]. Shortly, 13 female subjects (164.1±5.6 cm, 67.7±12.3 kg, 40.6±8.3 years), which were familiar with walking in high heels and did not suffer from recent lower extremity pain, were recruited for this investigation and signed informed consent forms. Four types of commercially available dress shoes were chosen for this study. They were of similar construction with the main difference in the height of the heel (14, 37, 54
Results
Both approaches, the time discrete as well as the time course oriented approach, identified individual gait patterns when pattern recognition was applied separately for each heel height. The ARs were in both cases close to 100% (Table 1, Table 2).
For the time discrete approach, the identification of individual gait characteristics was highest when using all variables together (Table 1, column ‘All’) but almost as high when using the minimum parameter (column ‘Minima’). A decrease of the AR was
Discussion
In the present investigation subject specific gait characteristics could be identified by means of time discrete and time continuous approaches. The recognition rates of 93.1–100% for individuals with respect to each heel height condition confirm the previous results for the individuality of specific movement patterns found for running, discus and javelin throwing [5], [6], [7]. The probability of finding all trials of each subject in separate clusters by random is extremely small. Therefore,
Conclusion
The results of this study have demonstrated that gait pattern contain general and individual information. Furthermore, the results of this study have shown that a time continuous data analysis approach using artificial neural networks provides an effective tool for identifying the subject specific and general characteristics for individuals and groups. The results of this study documented that the continuous data approach is more powerful in predicting subject specific and group specific
References (24)
- et al.
Pathophysiology of gait in children with cerebral palsy
EEG Clin. Neurophys.
(1982) - et al.
Fourier analysis of ground reaction forces in normals and patients with knee joint disease
J. Biomech.
(1983) - et al.
Assessment of gait patterns using neural networks
J. Biomech.
(1995) - et al.
Level, downhill and uphill walking identification using neural networks
Electr. Lett.
(1993) Visual perception of biological motion and a model for its analysis
Percept. Psychophys.
(1973)- et al.
Recognizing friends by their walk: gait perception without familiarity cues
Bull. Psychonomic. Soc.
(1977) - et al.
Self-organizing maps for the analysis of complex movement patterns
Neur. Proc. Lett.
(1997) - et al.
Identifying individual movement styles in high performance sports by means of self-organizing Kohonen maps
- et al.
Erkennung von individuellen Laufmustern mit Hilfe von neuronalen Netzen (recognition of individual running patterns by means of artificial neural nets)
- Stefanyshyn D, Nigg B, Fisher V, O'Flynn B, Liu W. The influence of high heeled shoes on kinematics, kinetics and...
Energetic cost and stability during human walking at the preferred stride frequency
J. Motor Behav.
A more pragmatic critria for filtering data
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