The amplitudes of activation for adductor magnus muscle is 33, 35 and 34 respectively for all three cases in left leg and in the right leg are 23, 5 and 4.
Further, we found adductor magnus to be the third most active muscle, in the absence of the prime mover.
These included the quadriceps, hamstrings, gluteus maximus, posterior adductor magnus
, and erector spinae bilaterally, which were all activated by the implanted stimulator.
Gluteus medius and adductor magnus induced the largest COM accelerations in the ML dimension.
The muscle groups most active in driving the system COM in the right and left directions were the right adductor magnus and right gluteus medius, respectively.
Case 1 allowed for all segments to be activated individually, whereas cases 2 to 5 required the various elements of several muscles to be activated equally: the latissimus dorsi, gluteus maximus, hamstrings, posterior portion of the adductor magnus, and abdominals.
Additionally constraining the various elements of the abdominals, hamstrings, and posterior portion of the adductor magnus to have equal activations (cases 3-5) showed decreasing performance, especially with the constrained activation of the abdominals.
Model simulations indicated that the required abduction moments were produced almost entirely by gluteus medius and hip adduction moments were produced almost entirely by adductor magnus.
These muscles were medial gastrocnemius for plantar flexion, tibialis anterior for dorsiflexion, vastus intermedius for knee extension, semimembranosus for knee flexion, adductor magnus for hip adduction, gluteus medius for hip abduction, gluteus maximus for hip extension, and erector spinae for trunk pitch and roll.