Results
The results focus on the effect of the personalized mus- cle geometry on the force generation in the lower limb. DistMo defines the model personalized with the PA ob- tained with the straight line approach, while CenMo describes the model personalized with the PA obtained with the centroid line approach. GenMo represents the model that used the generic values of the PA from OpenSim (PARF = 13.9◦, PAV I = 4.5◦, PAV L = 18.4◦,
PAV M = 29.6◦). The inter-model force and moment variations between GenMo, DistMo, and CenMo were calculated for the Toe Off - Heel Striking interval of the gait cycle, when the subject was hitting the force plates and for the deep squat exercise. We analyzed four motion capture data sets: two for gait (Subject1 …show more content…
The moments, tendon and muscle forces of VM are overestimated by the generic model with 30.04% with respect to DistMo and 31.13% with respect to CenMo. In contrast, they are underestimated in the case of VI with 22.30% with respect to DistMo and 22.65% with respect to CenMo. These two largest variations can be explained by the high differences between the generic and estimated pennation angle for VM and VI. The average computational value for VM is smaller with 11.34◦ than the generic value, while the difference be- tween the average calculated and generic value of VI is 12.58◦. Similar patterns were obtained for RF and VL. The moments and forces were overestimated for RF and underestimated for VL. However, for these two muscles the variations between GenMo and DistMo, respective CenMo were smaller in comparison with VI and VM. The under- and over-estimations of the generic model for Subject1 with respect to DistMo and CenMo were for RF and VL: 3.79% and 4.25% for RF, and 8.84% and 4.37% for VL. Comparable under- and over-estimations were obtained also for the other subjects. In average, the generic model overestimated the pennation angle of the RF and VM with 3.65%, and respectively 32.21%, while pennation angle of the VI and VL were underes- timated with 21.29%, and respectively …show more content…
The RF muscle presented the largest shape variation between Subject1 and Subject2.
Discussion
This study compared the moments and muscle forces (tendon force and total muscle fiber force) generated using generic and personalized pennation angle for the based on the Laplace equation, while the line of ac- tion is determined using a straight- and - centroid line approach. We investigated the effect of the pennation angle for three healthy volunteers in two scenarios: deep squat and gait cycle. To our knowledge, this is the first study that calculates 3D pennation angle using a single image acquisition technique (MRI) and assesses the ef- fect of subject-specific pennation angle on gait analysis.
The average pennation angle caculated for the quadri- quadriceps muscles for three healthy volunteers with ceps muscle were: 9.72◦ ± 1.52◦ for RF,
The results focus on the effect of the personalized mus- cle geometry on the force generation in the lower limb. DistMo defines the model personalized with the PA ob- tained with the straight line approach, while CenMo describes the model personalized with the PA obtained with the centroid line approach. GenMo represents the model that used the generic values of the PA from OpenSim (PARF = 13.9◦, PAV I = 4.5◦, PAV L = 18.4◦,
PAV M = 29.6◦). The inter-model force and moment variations between GenMo, DistMo, and CenMo were calculated for the Toe Off - Heel Striking interval of the gait cycle, when the subject was hitting the force plates and for the deep squat exercise. We analyzed four motion capture data sets: two for gait (Subject1 …show more content…
The moments, tendon and muscle forces of VM are overestimated by the generic model with 30.04% with respect to DistMo and 31.13% with respect to CenMo. In contrast, they are underestimated in the case of VI with 22.30% with respect to DistMo and 22.65% with respect to CenMo. These two largest variations can be explained by the high differences between the generic and estimated pennation angle for VM and VI. The average computational value for VM is smaller with 11.34◦ than the generic value, while the difference be- tween the average calculated and generic value of VI is 12.58◦. Similar patterns were obtained for RF and VL. The moments and forces were overestimated for RF and underestimated for VL. However, for these two muscles the variations between GenMo and DistMo, respective CenMo were smaller in comparison with VI and VM. The under- and over-estimations of the generic model for Subject1 with respect to DistMo and CenMo were for RF and VL: 3.79% and 4.25% for RF, and 8.84% and 4.37% for VL. Comparable under- and over-estimations were obtained also for the other subjects. In average, the generic model overestimated the pennation angle of the RF and VM with 3.65%, and respectively 32.21%, while pennation angle of the VI and VL were underes- timated with 21.29%, and respectively …show more content…
The RF muscle presented the largest shape variation between Subject1 and Subject2.
Discussion
This study compared the moments and muscle forces (tendon force and total muscle fiber force) generated using generic and personalized pennation angle for the based on the Laplace equation, while the line of ac- tion is determined using a straight- and - centroid line approach. We investigated the effect of the pennation angle for three healthy volunteers in two scenarios: deep squat and gait cycle. To our knowledge, this is the first study that calculates 3D pennation angle using a single image acquisition technique (MRI) and assesses the ef- fect of subject-specific pennation angle on gait analysis.
The average pennation angle caculated for the quadri- quadriceps muscles for three healthy volunteers with ceps muscle were: 9.72◦ ± 1.52◦ for RF,