Fig. 4

a) Correlation between the net cardiopulmonary metabolic energy cost and percentage of MVC in the stance phase of the gait cycle during inclined treadmill walking (*p < 0.05). b) Correlation between net cardiopulmonary metabolic energy cost and the percentage of MVC in the swing phase of the gait cycle during inclined treadmill walking. RA, rectus abdominis; ES, erector spinae; RF, rectus femoris; BF, biceps femoris; VM, vastus medialis; TA, tibialis anterior; GCM, medial head of the gastrocnemius; SOL, soleus (*p < 0.05)