EMG-FM-Bench: A Comprehensive Benchmark for Foundation Model Transfer and Adaptation on Electromyography
Organizations: University of Georgia · University of Oklahoma · University of Massachusetts Amherst
Abstract
Foundation models (FMs) are increasingly being developed for general time series and physiological signals, yet their transferability to downstream physiological tasks remains poorly understood. This question is particularly challenging for electromyography (EMG), where signal distributions vary substantially across users, sensing configurations, acquisition hardware, and downstream tasks. We introduce EMG-FM-Bench, a systematic benchmark for studying foundation-model transfer and adaptation on EMG. EMG-FM-Bench unifies 20 public datasets with over 1 million EMG segments and evaluates nine pretrained foundation models across four questions: how pretrained models perform when frozen or fully fine-tuned, how much pretraining helps compared with training the same model from scratch, how well models generalize to new users with limited labeled data, and how performance changes across different EMG tasks. Across the benchmark, linear probing provides useful information about pretrained representations, but full fine-tuning can substantially change downstream EMG performance. Comparing each pretrained model with the same model trained from scratch shows that the benefit of pretraining varies substantially across models and is not universal. Performance decreases when models are evaluated on new users, while five-shot adaptation improves macro-F1 in 70.2% of evaluated model-dataset combinations but recovers only part of the lost performance. Model performance is highly consistent between upper- and lower-limb classification and remains strongly correlated with continuous EMG-to-text decoding. Together, these results provide a systematic view of when pretrained time-series models transfer effectively to EMG and how their performance depends on fine-tuning, user variation, and downstream task.
Figures & tables
| Category | # Data | # Subj. | # Windows | Benchmark Task |
|---|---|---|---|---|
| Upper limb | 15 | 489 | 574,182 | Gesture/pose classification |
| Lower limb | 4 | 156 | 54,953 | Locomotion classification |
| Typing | 1 | 108 | 402,119 | Character sequence decoding |
| Total | 20 | 753 | 1,031,254 | Classification and Seq2Seq |
| Model | Architecture | Pretraining Domain | Params. |
|---|---|---|---|
| MOMENT-S/B [ 13 ] | Encoder-only Transformer | Heterogeneous time series | 40M / 125M |
| Chronos-2-S/B [ 14 ] | Encoder-only Transformer | General forecasting data | 28M / 120M |
| TimesFM [ 20 ] | Decoder-only Transformer | General time series | 200M |
| Lag-Llama [ 22 ] | Decoder-only Transformer | General time series | 2.45M |
| PatchTST [ 56 ] | Encoder-only Transformer | General time series | 1M |
| UniTS [ 57 ] | Modified Transformer | Heterogeneous time series | 3.4M |
| Model | LP | FFT | Scratch | Held-out | LOSO | 5-shot (F1) |
|---|---|---|---|---|---|---|
| MOMENT-S | 41.9 (2.5) | 60.1 (2.1) | 57.4 (2.1) | 39.0 (3.3) | 34.9 (3.8) | 42.7 (2.6) |
| MOMENT-B | 52.2 (1.2) | 46.8 (4.4) | 57.3 (2.1) | 28.1 (5.7) | 35.6 (3.9) | 40.0 (3.5) |
| BRANT | 18.2 (7.5) | 22.8 (8.0) | 20.8 (8.5) | 19.8 (7.6) | 23.0 (6.9) | 12.5 (8.3) |
| PatchTST | 20.2 (7.1) | 30.1 (7.4) | 30.7 (6.9) | 27.2 (5.6) | 19.6 (8.6) | 16.3 (7.1) |
| TimesFM | 29.4 (5.2) | 37.9 (5.9) | 31.6 (6.8) | 31.1 (5.0) | 34.2 (4.6) | 27.6 (5.3) |
| Chronos-2-S | 28.1 (4.6) | 54.3 (3.1) | 38.2 (4.8) | 41.6 (3.2) | 36.7 (3.6) | 44.0 (2.9) |
| Model | Mean Acc | Improved (F1) |
|---|---|---|
| MOMENT-S | +18.2 | 18/19 |
| MOMENT-B | -5.4 | 6/19 |
| BRANT | +4.6 | 14/19 |
| PatchTST | +9.9 | 18/19 |
| TimesFM | +8.5 | 15/19 |
| Chronos-2-S | +26.2 | 19/19 |
| Model | Drop | Gain | ||
|---|---|---|---|---|
| MOMENT-S | -27.1 | 18/19 | +11.9 | 16/19 |
| MOMENT-B | -22.4 | 18/19 | +18.3 | 19/19 |
| BRANT | -2.5 | 13/19 | +1.2 | 13/19 |
| PatchTST | -6.3 | 15/19 | -3.5 | 6/19 |
| TimesFM | -10.4 | 15/19 | +4.2 | 13/19 |
| Chronos-2-S | -19.1 | 18/19 | +10.9 | 15/19 |
| Dataset | MOMENT-S | MOMENT-B | BRANT | PatchTST | TimesFM | Chronos-2-S | Chronos-2-B | Lag-Llama | UniTS |
|---|---|---|---|---|---|---|---|---|---|
| emg2qwerty | 26.8 | 24.4 | 54.9 | 46.8 | 51.8 | 24.0 | 19.7 | 38.0 | 29.8 |
Appendix figures & tables8 assets
Supplementary material from the paper’s appendix.
Appendix
| Dataset | MOMENT-S | MOMENT-B | BRANT | PatchTST | TimesFM | Chronos-2-S | Chronos-2-B | Lag-Llama | UniTS |
|---|---|---|---|---|---|---|---|---|---|
| NinaPro DB1 | 43.6/48.1 | 32.5/35.8 | 22.0/24.1 | 22.2/25.5 | 38.9/39.6 | 42.5/46.6 | 44.8/49.0 | 17.5/12.5 | 36.1/39.0 |
| NinaPro DB2 | 55.4/55.2 | 26.1/25.6 | 3.5/1.0 | 6.8/6.2 | 17.4/16.4 | 56.6/56.7 | 49.2/49.3 | 2.4/0.2 | 12.8/11.6 |
| NinaPro DB3 | 28.1/28.1 | 13.0/12.0 | 3.7/0.6 | 2.1/2.1 | 3.7/2.3 | 22.9/22.0 | 21.7/20.9 | 2.7/0.4 | 5.6/3.2 |
| NinaPro DB4 | 44.3/45.5 | 23.7/22.5 | 4.0/0.5 | 9.5/8.2 | 9.2/8.0 | 34.1/35.5 | 40.5/43.1 | 4.5/0.4 | 12.6/11.5 |
| NinaPro DB5 | 28.6/29.0 | 11.7/10.8 | 6.7/1.0 | 6.1/5.3 | 10.5/8.7 | 23.0/23.3 | 22.2/22.5 | 6.4/1.2 | 10.8/7.8 |
| NinaPro DB6 | 51.0/53.1 | 38.2/38.3 | 15.7/9.9 | 21.4/21.4 | 43.0/32.4 | 58.9 /59.1 | 58.3/ 59.9 | 56.4/58.2 | 23.0/19.6 |
| Dataset | MOMENT-S | MOMENT-B | BRANT | PatchTST | TimesFM | Chronos-2-S | Chronos-2-B | Lag-Llama | UniTS |
|---|---|---|---|---|---|---|---|---|---|
| NinaPro DB1 | 26.5/26.8 | 32.0/35.5 | 11.9/8.9 | 9.7/7.8 | 6.3/4.3 | 16.6/18.1 | 16.8/17.7 | 15.7/11.3 | 10.8/5.5 |
| NinaPro DB2 | 20.5/20.6 | 33.0/31.9 | 0.9/0.0 | 2.3/1.0 | 5.7/5.1 | 8.2/6.2 | 8.2/6.4 | 1.7/0.1 | 2.5/0.8 |
| NinaPro DB3 | 8.7/8.9 | 19.6/19.0 | 0.2/0.0 | 2.3/0.8 | 2.3/1.1 | 3.5/2.0 | 3.9/2.0 | 2.9/0.5 | 2.5/1.3 |
| NinaPro DB4 | 23.0/19.5 | 33.4/34.6 | 5.2/0.8 | 5.5/4.0 | 5.7/2.9 | 7.1/3.2 | 10.4/5.8 | 4.3/0.7 | 3.8/1.2 |
| NinaPro DB5 | 14.9/10.2 | 22.2/21.5 | 7.0/1.1 | 5.5/1.1 | 7.0/3.1 | 8.5/3.7 | 8.2/3.7 | 5.3/1.1 | 6.4/1.1 |
| NinaPro DB6 | 36.3/36.6 | 44.4/46.3 | 5.0/1.4 | 6.8/3.9 | 35.9/31.0 | 19.0/17.7 | 21.3/19.6 | 12.9/6.6 | 35.3/30.7 |
| Dataset | MOMENT-S | MOMENT-B | BRANT | PatchTST | TimesFM | Chronos-2-S | Chronos-2-B | Lag-Llama | UniTS | BiLSTM |
|---|---|---|---|---|---|---|---|---|---|---|
| NinaPro DB1 | 41.1/45.1 | 41.6/45.4 | 20.0/19.3 | 23.3/25.6 | 47.4/50.7 | 25.1/29.0 | 29.0/32.3 | 24.3/27.0 | 28.6/32.1 | 38.9/41.7 |
| NinaPro DB2 | 44.6/45.4 | 52.4/52.9 | 1.5/0.4 | 8.9/8.4 | 8.4/8.0 | 7.5/5.4 | 17.3/16.5 | 25.1/25.4 | 8.9/8.2 | 9.4/9.7 |
| NinaPro DB3 | 21.5/20.7 | 19.5/18.8 | 1.7/0.6 | 2.6/2.5 | 2.9/2.4 | 4.3/1.2 | 4.7/3.1 | 6.0/6.2 | 3.5/1.9 | 2.6/2.4 |
| NinaPro DB4 | 38.7/39.4 | 36.3/35.0 | 5.7/1.2 | 8.2/7.8 | 4.5/3.6 | 10.0/8.5 | 20.9/19.7 | 13.7/14.3 | 9.0/5.7 | 7.7/7.1 |
| NinaPro DB5 | 30.7/31.0 | 22.7/25.4 | 7.3/1.4 | 9.9/8.4 | 6.7/4.1 | 9.3/6.1 | 14.3/10.6 | 12.0/12.1 | 6.4/0.6 | 5.3/4.4 |
| NinaPro DB6 | 46.7/48.0 | 46.8/48.8 | 7.1/4.4 | 25.9/25.4 | 23.9/24.0 | 33.2/34.5 | 38.8/40.4 | 35.7/36.1 | 43.2/44.7 | 17.8/17.5 |
| Dataset | MOMENT-S | MOMENT-B | BRANT | PatchTST | TimesFM | Chronos-2-S | Chronos-2-B | Lag-Llama | UniTS | BiLSTM |
|---|---|---|---|---|---|---|---|---|---|---|
| NinaPro DB1 | 23.8/25.0 | 25.4/22.4 | 12.4/13.7 | 21.2/19.9 | 43.0/41.8 | 21.2/25.2 | 28.0/27.1 | 16.1/9.6 | 22.8/22.7 | 17.6/15.2 |
| NinaPro DB2 | 26.9/23.9 | 18.9/17.2 | 1.5/0.4 | 8.0/4.4 | 13.4/9.7 | 27.9/25.8 | 25.4/24.0 | 3.5/0.3 | 12.1/8.5 | 11.4/10.7 |
| NinaPro DB3 | 7.8/5.4 | 1.9/1.4 | 1.0/0.0 | 1.9/1.1 | 7.8/2.8 | 7.8/4.1 | 13.6/11.6 | 1.9/0.1 | 5.8/1.9 | 1.0/1.0 |
| NinaPro DB4 | 37.2 / 30.2 | 9.3/6.6 | 2.3/0.2 | 7.0/3.7 | 4.7/4.6 | 27.9/20.3 | 37.2 /28.1 | 2.3/0.2 | 14.0/11.9 | 11.6/10.5 |
| NinaPro DB5 | 25.0/ 26.0 | 9.4/4.3 | 6.3/0.7 | 6.3/3.2 | 12.5/7.4 | 31.3 /23.9 | 15.6/8.6 | 3.1/1.2 | 6.2/2.6 | 6.3/3.9 |
| NinaPro DB6 | 38.0/29.1 | 29.5/27.4 | 5.5/1.5 | 19.0/15.8 | 23.9/22.4 | 42.3/37.5 | 48.5/41.7 | 35.6/25.8 | 13.4/11.1 | 26.4/23.7 |
| Dataset | MOMENT-S | MOMENT-B | BRANT | PatchTST | TimesFM | Chronos-2-S | Chronos-2-B | Lag-Llama | UniTS | BiLSTM |
|---|---|---|---|---|---|---|---|---|---|---|
| NinaPro DB1 | ||||||||||
| NinaPro DB2 | ||||||||||
| NinaPro DB3 | ||||||||||
| NinaPro DB4 | ||||||||||
| NinaPro DB5 | ||||||||||
| NinaPro DB6 |
| Dataset | MOMENT-S | MOMENT-B | BRANT | PatchTST | TimesFM | Chronos-2-S | Chronos-2-B | Lag-Llama | UniTS | BiLSTM |
|---|---|---|---|---|---|---|---|---|---|---|
| NinaPro DB1 | ||||||||||
| NinaPro DB2 | ||||||||||
| NinaPro DB3 | ||||||||||
| NinaPro DB4 | ||||||||||
| NinaPro DB5 | ||||||||||
| NinaPro DB6 |
| Dataset | Sensor Location | Fs (Hz) | Channels | Task |
| Hand/Arm Gesture Datasets | ||||
| NinaPro DB1 [ 39 ] | Forearm | 100 | 10 | Hand Gesture Classification |
| NinaPro DB2 [ 39 ] | Forearm | 2000 | 12 | Hand Gesture Classification |
| NinaPro DB3 [ 39 ] | Forearm | 2000 | 12 | Hand Gesture Classification |
| NinaPro DB4 [ 40 ] | Forearm | 2000 | 12 | Hand Gesture Classification |
| NinaPro DB5 [ 40 ] | Forearm | 200 | 16 | Hand Gesture Classification |
| Model | Architecture | Pretraining Objective | Native Scope / Input | Params. |
|---|---|---|---|---|
| MOMENT-S/B | Encoder; patch tokens | Masked-patch reconstruction | Heterogeneous real-world numerical time series | 40M / 125M |
| Chronos-2-S/B | Encoder; temporal and group attention | Direct quantile forecasting | Univariate and multivariate targets with optional covariates | 28M / 120M |
| TimesFM | Decoder; patched input | Multi-horizon forecasting | Primarily univariate numerical time series | 200M |
| Lag-Llama | Decoder; lagged covariates | Autoregressive probabilistic forecasting | Univariate series with lag and temporal covariates | 2.45M |
| PatchTST | Encoder; channel-independent patching | Forecasting | General time series | 1M |
| BRANT | Temporal followed by spatial encoders | Masked-signal reconstruction | Multichannel iEEG/SEEG with time–frequency features | 500M |