Skip to main content
. Author manuscript; available in PMC: 2020 Mar 27.
Published in final edited form as: IEEE Trans Biomed Eng. 2019 Mar 28;66(12):3444–3456. doi: 10.1109/TBME.2019.2905956

Table VII. A Comparison of Root Mean Square Difference (RMSD) and Coefficient of Determination (R2) in Joint Reaction Forces Produced by the Scaled Generic Model and the Scaled Closest Model.

Ankle Knee Hip Sumc
Scaled-generic Scaled-closesta Scaled-generic Scaled-closest Scaled-generic Scaled-closest Scaled-generic Scaled-closest
RMSD (%) R2 RMSD (%) R2 RMSD (%) R2 RMSD (%) R2 RMSD (%) R2 RMSD (%) R2 RMSD (%) R2 RMSD (%) R2
M1 20 0.99 14 0.98 55 0.64 18 0.92 32 0.86 16 0.97 25 0.83 11 0.96
M2 43 0.76 13 0.98 37 0.82 15 0.97 32 0.81 11 0.98 38 0.80 13 0.98
M3 31 0.90 15 0.99 40 0.79 20 0.97 36 0.91 21 0.94 49 0.87 10 0.97
M4 43 0.79 5 0.99 55 0.76 13 0.93 19 0.97 16 0.97 54 0.84 11 0.96
M5 87 0.81 9 0.99 56 0.75 20 0.99 39 0.92 9 0.99 31 0.82 11 0.99
F1 13 0.99 10 0.99 37 0.89 10 0.99 43 0.86 17 0.98 47 0.91 5 0.99
F2 47 0.70 35 0.96 35 0.96 14 0.90 26 0.88 22 0.94 52 0.85 10 0.94
F3 51 0.17 28 0.94 57 0.55 12 0.99 48 0.94 30 0.99 34 0.56 17 0.97
F4 40 0.76 17 0.95 44 0.75 11 0.93 37 0.83 13 0.95 52 0.78 10 0.94
F5 64 0.57 18 0.89 69 0.54 30 0.89 24 0.94 10 0.93 79 0.68 27 0.91
Mean 44 0.72 16 0.97 48 0.76 16 0.95 34 0.90 17 0.96 46 0.79 13 0.96
SD 21 0.23 9 0.03 11 0.14 6 0.04 9 0.05 7 0.02 15 0.10 6 0.02
p valueb 0.005 0.005 0.005 0.005

M and F designate male and female.

a

The closest musculoskeletal model for scaling (scaled-closest) is derived from the multiple regression model with the minimum RMSD (min f(RMSDd)) in joint reaction forces: for the ankle, min f(RMSDd) = min (11.06 + 0.49 × Δmassd + 7.66 × Δgenderd) ; for the knee, min f(RMSDd) = min (5.32 + 1.00 × ΔLLd + 0.38 × Δmassd + 37.22 × Δratiod + 7.75 × Δgenderd) ; for the hip, min f(RMSDd) = min (9.60 + 0.38 × ΔLLd + 0.10 × Δmassd + 2.64 × Δgenderd); and for their sum, min f(RMSDd) = min (7.40 + 0.16 × Δmassd + 4.03 × Δgenderd + 0.16 × Δratiod), where: Δgenderd indicates the difference in gender between the subject and the model (d), which is 1 when gender is different else is 0; Δmassd, ΔLLd and Δratiod indicate the percentage difference in mass, limb length (LL) and the limb length to pelvis width ratio from the underlying dataset (d) to the modelled subject.

b

p value is from the Wilcoxon Signed Rank test between RMSDs from scaled-generic and scaled-closest models (α = 0.05).

c

RMSDs of the sum of joint reaction forces of ankle, knee and hip; R2 is the mean R2 in joint reaction forces of ankle, knee and hip.