Loadings from a principal components analysis including 13 variables related to pMG muscle function
| Variable . | PC1 . | PC2 . | PC3 . |
|---|---|---|---|
| Strainforce onset to force max | –0.08 | 0.94 | 0.23 |
| Strainforce max to force offset | 0.60 | –0.14 | 0.17 |
| Strainswing | –0.80 | –0.23 | –0.37 |
| Strainnet | 0.23 | 0.86 | 0.31 |
| Forcemax | 0.95 | 0.02 | –0.13 |
| Forcemean | 0.97 | 0.01 | 0.05 |
| Forceduration | –0.01 | –0.30 | 0.93 |
| Stressmax | 0.70 | –0.57 | –0.38 |
| Stressmean | 0.75 | –0.54 | –0.16 |
| EMGduration | 0.14 | –0.19 | 0.91 |
| EMGonset relative to force onset | 0.00 | 0.66 | –0.37 |
| MSA | 0.56 | 0.54 | –0.45 |
| RIA | 0.67 | 0.40 | 0.23 |
| Variable . | PC1 . | PC2 . | PC3 . |
|---|---|---|---|
| Strainforce onset to force max | –0.08 | 0.94 | 0.23 |
| Strainforce max to force offset | 0.60 | –0.14 | 0.17 |
| Strainswing | –0.80 | –0.23 | –0.37 |
| Strainnet | 0.23 | 0.86 | 0.31 |
| Forcemax | 0.95 | 0.02 | –0.13 |
| Forcemean | 0.97 | 0.01 | 0.05 |
| Forceduration | –0.01 | –0.30 | 0.93 |
| Stressmax | 0.70 | –0.57 | –0.38 |
| Stressmean | 0.75 | –0.54 | –0.16 |
| EMGduration | 0.14 | –0.19 | 0.91 |
| EMGonset relative to force onset | 0.00 | 0.66 | –0.37 |
| MSA | 0.56 | 0.54 | –0.45 |
| RIA | 0.67 | 0.40 | 0.23 |
PC1, PC2 and PC3 explained 36.4, 25.5 and 19.9% of the total variance,respectively
pMG, proximal region of the medial gastrocnemius; EMG, electromyogram; MSA,mean spike amplitude of the EMG burst; RIA, rectified integrated area of the EMG burst
Loadings >0.6 are in bold