Table 1 A comparison of modeling approaches in HAR for physiotherapy.

From: Spike train analysis in rehabilitation movement classification using deep learning approach

Approach

Input representation

Strengths

Limitations

References

CNN (image/video)

RGB frames, depth maps

Strong in spatial feature extraction, widely benchmarked

High dimensionality, sensitive to lighting/occlusion

31,32,33

Skeleton-based GCN

Skeleton joints as graph nodes

Captures joint dependencies; spatial–temporal modeling

Requires accurate joint detection; less robust to noise

28,29,34,35

ST-GCN

Skeleton sequences with temporal graph edges

Models spatial and temporal dynamics simultaneously

Computationally heavy; sensitive to missing joints

36

RNN/LSTM

Skeleton joint sequences

Effective for temporal dependencies

Struggles with long-range dependencies

32,34,37

Time–frequency/Heatmaps

Transformed motion signals

Rich spectral–temporal features; interpretable

Preprocessing overhead

38

Spike train encoding (Proposed)

Rasterized spike trains from skeletal data

Bio-inspired, temporally sparse, highlights movement correctness

Novel approach, requires adaptation of classifiers

Proposed