Fourier-Based Footfall Placement Variability in Parkinson’s Disease

<p><i>Footfalls of a healthy and a low PD person.</i> (a) The COP coordinates of each footfall from a representative trial by a healthy control participant are shown. The footfall pattern was the best fit with a <svg height="12.3641pt" id="M4" style="vertical-align:-0.2064009pt" version="1.1" viewbox="-0.0498162 -12.1577 15.1366 12.3641" width="15.1366pt" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M285 378C315 398 338 416 353 432C373 451 384 474 384 503C384 579 325 635 236 635H235C182 635 136 610 108 579L65 516L85 496C110 533 150 575 205 575C258 575 300 543 300 481C300 407 232 369 141 339L147 310C163 315 188 321 211 321C268 321 338 284 338 192C338 94 288 40 217 40C160 40 119 68 93 91C85 98 77 97 69 91C60 84 47 71 46 58C44 46 48 35 62 22C75 10 116 -12 162 -12C234 -12 424 62 424 224C424 297 373 359 285 376V378Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,6.24,-5.741)"><path d="M185 344V453C137 433 92 421 41 413V386C100 378 104 375 104 310V106C104 41 97 35 33 30V0H268V30C190 35 185 41 185 107V283C206 340 240 371 267 371C282 371 296 364 310 351C316 344 325 343 336 348C357 357 369 378 369 399C369 424 345 451 310 451C262 451 219 397 187 344H185Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,9.589,-5.741)"><path d="M526 56L493 58C457 61 448 68 448 119V710C411 697 344 682 288 675V646C362 641 367 639 367 573V439C344 448 315 451 300 451C164 451 40 342 40 202C40 61 147 -12 227 -12C239 -12 266 -7 305 16L367 53V-12C427 10 505 21 526 26V56ZM367 88C342 69 306 54 271 54C207 54 133 111 133 229C133 373 219 409 264 409C301 409 342 394 367 359V88Z"></path></g></svg> order Fourier series (FPV=3). (b) The COP coordinates of each footfall from a representative trial by a person with low PD. The pattern was fit with a <svg height="12.2075pt" id="M5" style="vertical-align:-0.04980087pt" version="1.1" viewbox="-0.0498162 -12.1577 14.7256 12.2075" width="14.7256pt" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M456 178V225H360V632H320C217 496 115 347 20 206V178H280V106C280 40 276 34 189 27V0H445V27C364 34 360 39 360 106V178H456ZM280 225H82C149 335 214 431 278 520H280V225Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,6.24,-5.741)"><path d="M303 37L293 66C280 59 256 49 231 49S173 63 173 143V396H281C294 404 298 428 287 439H173V575L158 577L92 509V439H46L17 408L22 396H92V107C92 27 128 -12 192 -12C203 -12 218 -9 237 2L303 37Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,9.125,-5.741)"><path d="M522 0V30C462 35 455 41 455 106V280C455 397 397 451 314 451C262 451 206 414 171 379V710C131 698 69 682 20 675V647C87 642 90 637 90 574V106C90 41 80 35 20 30V0H236V30C176 35 171 43 171 106V339C198 371 237 391 276 391C341 391 374 350 374 269V106C374 43 367 35 308 30V0H522Z"></path></g></svg> order Fourier series (FPV=4). The walking direction was left to right.</p>

BioMed Research International

fig1

Figure 1

Figure 1: Fourier-Based Footfall Placement Variability in Parkinson’s Disease 