Table 4 Normalized differences in electromyographic delays associated with two cervical and upper thoracic spinal manipulations delivered following one another in quick succession in asymptomatic and symptomatic participants

Asymptomatic

1

0.0836⁺ ± 0.0438^#

0.0768 ± 0.0402

0.0501 ± 0.0291

0.0649 ± 0.0446

0.0724 ± 0.0283

0.0518 ± 0.0337

0.0475 ± 0.0290

0.0587 ± 0.0304

0.0852 ± 0.0407

0.0798 ± 0.0481

0.0582 ± 0.0278

0.0531 ± 0.0264

0.0723 ± 0.0238

0.0503 ± 0.0275

0.0484 ± 0.0234

0.0433 ± 0.0204

2

0.0543 ± 0.0436

0.0581 ± 0.0380

0.0374 ± 0.0266

0.0281 ± 0.0163

0.0500 ± 0.0310

0.0388 ± 0.0340

0.0359 ± 0.0423

0.0392 ± 0.0183

0.0759 ± 0.0546

0.0472 ± 0.0249

0.0260 ± 0.0207

0.0438 ± 0.0319

0.0491 ± 0.0108

0.0409 ± 0.0375

0.0379 ± 0.0458

0.0287 ± 0.0173

% diff

−35.06

−24.32

−25.38

−56.75

−30.92*

p = 0.004

−25.05

−24.49

−33.19

−10.82

−40.81

−55.30*

p < 0.001

−17.53

−32.09

−18.82

−21.61

− 33.70

Symptomatic

1

0.0445 ± 0.0288

0.0496 ± 0.0472

0.0239 ± 0.0173

0.0438 ± 0.0532

0.0372 ± 0.0271

0.0175 ± 0.0162

0.0272 ± 0.0221

0.0536 ± 0.0590

0.0577 ± 0.0355

0.0521 ± 0.0551

0.0228 ± 0.0185

0.0371 ± 0.0372

0.0386 ± 0.0261

0.0180 ± 0.0182

0.0283 ± 0.0281

0.0286 ± 0.0213

2

0.0593 ± 0.0516

0.0338 ± 0.0258

0.0198 ± 0.0257

0.0363 ± 0.0413

0.0336 ± 0.0289

0.0210 ± 0.0270

0.0222 ± 0.0236

0.0311 ± 0.0304

0.0413 ± 0.0261

0.0448 ± 0.0514

0.0162 ± 0.0158

0.0317 ± 0.0408

0.0510 ± 0.0610

0.0223 ± 0.0289

0.0303 ± 0.0298

0.0339 ± 0.0522

% diff

33.15

−31.69

−17.08

−17.20

−9.74

20.51

−18.33

−41.91

−28.32

−14.06

−28.77

−14.54

32.04

23.71

6.97

18.69