1. Hyperactive tendon reflexes in spastic multiple sclerosis: Measures and mechanisms of action 
Li-Qun Zhang, PhD, Guangzhi Wang, MS, Takashi Nishida, MD, Dali Xu, PhD, James A. Sliwa, DO, W.Zev Rymer, MD, PhD 
Archives of Physical Medicine and Rehabilitation 
Volume 81, Issue 7, Pages (July 2000)
DOI: /apmr
Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

2. Fig. 1
Representative patellar tendon tapping from a control subject (left column) and a spastic MS subject (subject E in table 1) (right column) over multiple taps with the knee at 75 °flexion: (top) the tendon tapping source; (middle) quadriceps EMG signal; and (bottom) reflexive joint extension torque. Solid lines, mean of each signal; dashed lines, mean ± standard deviation of each signal. The small bump following the tapping force peak in the MS patient (top right subplot) is the tendon bounce-back force that is not analyzed here and does not affect the current analysis.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

3. Fig. 2
Tendon reflex input and output with the knee at 75° flexion, limb muscles relaxed. (A) Tapping force threshold fth of MS patients was significantly lower than that of normal controls; (B) peak tendon reflex torque Mp of MS patients was significantly higher than that of normal controls. The vertical lines show the standard deviations across subjects in each population.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

4. Fig. 3
Peak reflex torque as a function of peak tapping force in 14 normal (circles) and 10 MS (squares and diamonds) subjects. The 10 MS patients are identified as A, B, C, D, E, F, G, H, I; and J (see table 1). The squares and diamond shapes represent MS patients with nonzero and zero Ashworth scale, respectively. The vertical and horizontal lines at each shape represent the standard error of the mean of the peak tapping force and peak reflex torque across multiple taps of each subject, respectively.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

5. Fig. 4
Representative impulse response (hMf(t)) of the patellar tendon reflex obtained through scaling of the reflex torque responses from a healthy subject (solid lines) and from a spastic MS patient with hyperactive tendon reflexes (dashed lines). From left to right, the three solid vertical lines correspond to the instant of the tapping force onset, the start of the reflex torque, and the peak reflex torque of the normal subject. From left to right, the two intervals between the three vertical lines correspond to td and tcr respectively. The three dashed vertical lines indicate the similar instant for the MS subject. The two impulse responses were aligned by the onset of the tapping force (the first vertical line). The peaks of the impulse responses correspond to the Gtr.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

6. Fig. 5
Tendon reflex with knee at 75 ° flexion, limbs relaxed, in 14 normal subjects and 10 MS patients. (A) Tendon reflex gain Gtr of MS patients was significantly higher than that of normal controls; (B) Contraction rate Rc of MS patients was significantly higher than that of normal controls; (C) Reflex loop delay of rate td of MS patients was significantly shorter than that of normal controls. The vertical lines show the standard deviations across subjects in each population.
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

7. Fig. 6
Representative relationship between the peak reflex torque of knee extension and the peak tendon tapping force (knee flexion angle 75 °) when the quadriceps tendon was tapped over a wide range of tapping force. The experiment was done on an MS patient (□ and 3rd-order polynomial) with hypereflexia and a normal subject (◁ and 2nd-order polynomial).
Archives of Physical Medicine and Rehabilitation  , DOI: ( /apmr )
Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions