Electrical stimulation: Can it increase muscle strength and reverse osteopenia in spinal cord injured individuals?  Marc Bélanger, PhD, Richard B. Stein, DPhil, Garry D. Wheeler, PhD, Tessa Gordon, PhD, Bernard Leduc, MD  Archives of Physical Medicine and Rehabilitation  Volume 81, Issue 8, Pages 1090-1098 (August 2000) DOI: 10.1053/apmr.2000.7170 Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 1 Absolute bone mineral density (BMD) for control (■) and for the left (□) and right (▨) sides of subjects with SCI before training. The three regions are statistically different from each other, both for the control and SCI subjects (p < .05). The lower bone densities in the SCI subjects are also significantly different from control subjects in all three regions (indicated by the asterisk above the bars). The BMD expressed as a percentage of control values are indicated at the bottom of the bars. Archives of Physical Medicine and Rehabilitation 2000 81, 1090-1098DOI: (10.1053/apmr.2000.7170) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 2 Bone mineral density (BMD) of the (A) distal femur, (B) proximal tibial, and (C) mid-tibia for controls (symbols having means ± standard error at years n = 0) and for subjects with SCI as a function of time after the SCI. The other points represent the pooled data for the right and left side for each of the 12 SCI subjects. (D) The BMD for the 3 regions are expressed as a percentage of the initial values obtained from the regression equations for the SCI subjects. Archives of Physical Medicine and Rehabilitation 2000 81, 1090-1098DOI: (10.1053/apmr.2000.7170) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 3 Change in bone mineral density (BMD) (mean ± standard error) as a result of (A) training in absolute units (g/cm2) and (B) as a percentage of the values in control subjects. The asterisks indicate significant differences at p < .05. Archives of Physical Medicine and Rehabilitation 2000 81, 1090-1098DOI: (10.1053/apmr.2000.7170) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 4 The change in bone density with functional electrical stimulation training is plotted (A) as a function of the value before training, and (B) as a function of the time after SCI when training was begun. The points are the bone mineral density for the distal femur and proximal tibia of both limbs. The three lines in (B) are the regression line (bold) and the 95% confidence intervals. Archives of Physical Medicine and Rehabilitation 2000 81, 1090-1098DOI: (10.1053/apmr.2000.7170) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 5 Curves of the torques at the beginning (solid line) and end (dashed and dotted lines) of the 24-week training period. The downward-pointing arrow shows the onset of a spasm in one of the first contractions of the last recording session. The double-ended arrow at the bottom of the graph indicates the region where the torque measurements were taken (ie, avoiding the initial overshoot and the spasm). The small vertical lines represent the stimuli (ie, 40Hz for 2sec). It should be noted that a 0-Nm torque is recorded when the muscle contraction is not strong enough to move the leg at the set speed of the isokinetic dynamometer (eg, the torque trace at the beginning of training is null beyond 500msec). Archives of Physical Medicine and Rehabilitation 2000 81, 1090-1098DOI: (10.1053/apmr.2000.7170) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 6 Increase in strength in the resisted (solid lines) and unresisted limbs (dashed lines) as a function of the duration of training. The thick lines represent the regression lines, the thin lines give the 95% confidence intervals. Archives of Physical Medicine and Rehabilitation 2000 81, 1090-1098DOI: (10.1053/apmr.2000.7170) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions

Fig. 7 The change in torque as a result of training is plotted against the torque at the start of training for the resisted (solid line) and unresisted (dashed line) sides (A) and as a percentage of the initial torque (B). The lines in (A) represent the mean change. The regression equation in (B) is described in the text. Archives of Physical Medicine and Rehabilitation 2000 81, 1090-1098DOI: (10.1053/apmr.2000.7170) Copyright © 2000 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation Terms and Conditions