1. Effects of Multijoint Spastic Reflexes of the Legs During Assisted Bilateral Hip Oscillations in Human Spinal Cord Injury 
Tanya Onushko, MS, Allison Hyngstrom, PhD, Brian D. Schmit, PhD 
Archives of Physical Medicine and Rehabilitation 
Volume 91, Issue 8, Pages (August 2010)
DOI: /j.apmr
Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions

2. Fig 1
(A) Experimental apparatus used to impose bilateral hip oscillations and record sagittal plane torques during hip movements. Two servomotor systems were used to impose movements about the hips. Joint torques were recorded using torque transducers aligned with the hip, knee, and ankle joints of both legs. (B) Each leg was moved through 50° of rotation about the hip (40° hip flexion to 10° hip extension). (C) Illustration of the hip position traces for the right (solid) and left (dashed) hip for (i) .25-Hz, (ii) .50-Hz and (iii) .75-Hz movement frequencies. The legs were moved in an alternating manner for all tests (180° out of phase).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions

3. Fig 2
Example of the conversion of the torque data into the vector and phase angle representation. (A) One cycle of hip position (dotted trace) and corresponding hip torque response (solid trace) plotted against the polar angle. The gray shaded background on the torque response represents hip flexion torque. (B) Hip flexion torque plotted in polar coordinates, where 180° represents the position of the hip in full extension (ie, −10°) and 0° represents the position of the hip in full flexion (ie, 40°). (C) A unit vector (radius, r=1) was used to represent the normalized magnitude of the peak torque, and the polar angle, θ, represents the timing of the peak torque generation with respect to the position of the hip for one movement cycle (ie, 0°–360°). Hip extension torque was calculated in a similar manner (not shown).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions

4. Fig 3
(A) Representative active torque traces during assisted and unassisted tests from SCI subject S7. Left column, SCI-unassisted; right column, SCI-assisted. Shaded areas represent flexion torques; unshaded areas represent extension torques. (B) EMG traces from SCI and control subjects. Left column, representative EMG traces during assisted (positive rectified) and unassisted (negative rectified) tests from SCI subject S7. Right column, representative EMG traces from a neurologically intact control subject. Activity during unassisted and assisted movements for SCI subjects did not differ in timing with respect to the position of the hip.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions

5. Fig 4
Hip and knee torque responses of SCI subjects during unassisted and assisted bilateral hip oscillations (.75Hz shown only). Each solid black line represents the average response from a single SCI subject. Under the assisted condition, the thick gray line represents the 95% confidence interval of hip and knee torque responses from control subjects. Vertical dashed lines indicate the peak hip flexion and extension portions of the hip movement. Typically, the responses in SCI subjects occurred at the time when the hip reached full extension or full flexion. The dashed black lines illustrate the responses from subjects S8 and S9, who generated patterns that more closely followed the pattern produced by the control subjects. In addition, these subjects did not produce responses under unassisted conditions.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions

6. Fig. 5
To obtain the timing of muscle activity during bilateral hip movements, the mean resultant vectors were plotted on a polar plane during assisted (SCI and control subjects) and unassisted (SCI only) tests. Full hip flexion corresponds to 0° and full hip extension corresponds to 180° on the polar plots. Hip extension torques are indicated within the shaded portion, and hip flexion torques are displayed over unshaded areas. The direction of hip motion is counterclockwise on the polar plane and is indicated by the curved arrow. Vector magnitudes (radius, r) represent the repeatability (r=1 is identical phase) of the measurements during the hip movements. Arrows represent the mean direction of the torque or EMG measurement with respect to the position of the hip throughout one cycle of movement. (A) Group mean right hip extension and flexion torques for all 3 movement frequencies. Significant differences were found from the resultant peak torque vectors between controls and SCI during the assisted test. (B) Resultant vectors for the group average EMG of the right leg muscles for the .75-Hz movement frequency only. The timing of MH and VL muscle activity significantly varied between the SCI and control groups for the assisted task. No significant differences were found between SCI subjects during assisted and unassisted tests for any EMG phase data. *P=.005.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /j.apmr )
Copyright © 2010 American Congress of Rehabilitation Medicine Terms and Conditions