Table 2. - The multiple regression models of the longitudinal plantar arch index (MLA) and rearfoot valgus alignment (REARFOOT) to predict the biomechanical dependent variables of runners with plantar fasciitis (PF): acute and chronic.
| Variables | Group | Beta Coefficient | Standard deviation | t | p& | Equation* | R, R2 |
|---|---|---|---|---|---|---|---|
| Force-Time Integral (N.s) (FTIF) |
Acute PF Chronic PF | 0.350 0.165 |
0.16 0.12 |
3.0 3.2 |
0.031 0.020 |
FTIF=0.211+0.350*MLA
FTIF=6.096+0.165*MLA |
r =0.35; R 2=0.15 r =0.41; R 2=0.17 |
| Maximal Force forefoot (N) (MFF) | Chronic PF | 1.850 | 0.81 | 2.2 | 0.043 | MFF=1.580+1.850*MLA | r =0.59; R 2=0.35 |
| Maximal Force rearfoot (N) (MFR) | Acute PF Chronic PF | 2.012 0.056 |
0.17 0.02 |
2.8 2.7 |
0.048 0.017 |
MFR=1.400+2.012*REARFOOT
MFR=2.140+0.056*REARFOOT |
r =0.42; R 2=0.18 r =0.67; R 2=0.45 |
| Force-Time Integral rearfoot (N.s) (FTIR) | Chronic PF | 0.103 | 0.12 | 3.8 | 0.041 | FTIR=2.840+0.103*REARFOOT | r =0.41; R 2=0.17 |
| Loading rate 20-80% Chronic PF (BW.s–1) |
0.278 | 0.01 | 1.6 | 0.013 | Loading rate (20-80%)
=0.645+0.278*REARFOOT |
r =0.44, R 2=0.19 | |
| Loading rate 0-100% Chronic PF (BW.s–1) |
1.238 | 0.14 | 1.8 | 0.012 | Loading rate (0-100%)
=7.54+1.238*REARFOOT |
r =0.63, R 2=0.40 | |
Acronyms: PF: Plantar Fasciitis; MLA: Medial Longitudinal Arch; REARFOOT: rearfoot valgus alignment; FTIF: Force-Time Integral; MFF: Maximal Force Forefoot; MFR: Maximal Force Rearfoot; FTIR: Force-Time Integral Rearfoot. & p-value of the multiple regression analyses. *Equations of the multiple regression analyses. The t-value and resulting p-value are used to test the hypothesis that the intercept is equal to 0.