Also note that in terms of differences in pelvic girdle between the two mice, the only factor that could influence the amplitude of tail movement in our model would be the wider base of support in pcd – which would actually predict that pcd mice would exhibit smaller amplitude tail oscillations than controls (because of smaller angular excursion of the hind paw axis).
As the flea approaches touchdown, the front legs are swung forward and downward, the middle legs are held perpendicular to the body axis, and the hind legs project obliquely posterior.
The adductor magnus and semimembranosus muscles of the left hind limb were imaged in short axis with a linear array transducer (L7-4), secured in position for the duration of the experiment, connected to an ultrasound system HDI-50000, Ultrasound, Phillips Ultrasound).
Also, S1P, acting via S1P1 and the 'VEFG axis,' is required for hind-limb angiogenesis and neovascularisation (Chae et al, 2004).
This allowed positioning of the hind limb close to the central scanner axis, preventing any movement of the limb during scanning.
We quantified this tendency by measuring the footprint alignment parameter, which corresponds to the mean standard deviation of the projection of the fore, mid, and hind footprints along the body's displacement axis.
The moments of inertia of the hind limb segments were individually calculated about their own neutral axis, in accordance with our previous studies [35].
The hind-limb paw angle (the angle of the hind paws during peak stance in relation to the long axis of the body and its direction of motion) showed a baseline value of 11.4 degrees, which also progressively decreased with increasing clinical scores, indicating that those paws with greatest swelling rotated inward during stance to be more parallel with the long axis of the body.
The hind legs were shaved and an incision was done on the outer side along the femur axis.
While under anesthesia, mice were placed in the prone position with the medial axis parallel to the axial axis of the scanner and the thorax, abdomen and hind legs placed into the center of the field of view of the microPET R4 or Inveon PET/computed tomography (CT) scanner (Siemens Preclinical Solutions, Knoxville, TN, USA).
The X axis shows time, and the two different bands indicate the contact durations of the right hind paw (RH) and left hind paw (LH) with the ground.
