The influence of physiologic and atmospheric variables on spasticity after spinal cord injury

Abstract

BACKGROUND: A number of physiological and atmospheric variables are believed to increase spasticity in persons with spinal cord injury (SCI) based on self-reported measures, however, there is limited objective evidence about the influence of these variables on spasticity. OBJECTIVE: We investigated the relationship between physiological/ atmospheric variables and level of spasticity in individuals with SCI. METHODS: In 53 participants with motor-incomplete SCI, we assessed the influence of age, time since injury, sex, injury severity, neurological level of injury, ability to walk, antispasmodic medication use, temperature, humidity, and barometric pressure on quadriceps spasticity. Spasticity was assessed using the pendulum test first swing excursion (FSE. To categorize participants based on spasticity level, we performed cluster analysis. We used multivariate stepwise regression to determine variables associated with spasticity level. RESULTS: Three spasticity groups were identified based on severity level: low, moderate, and high. The regression analysis revealed that only walking ability and temperature were significantly related to spasticity. CONCLUSIONS: These outcomes validate the self-reported perception of people with SCI that low temperatures worsen spasticity. The findings refine prior evidence that people with motor-incomplete SCI have higher levels of spasticity, showing that those with sufficient motor function to walk have the highest levels of spasticity.

A portable system to measure knee extensor spasticity after spinal cord injury

“…In agreement with previous studies [ 22 ], in control subjects, we found mean FSA values around 114° with the optical tracking system (range = 92.2° to 132°) and around 118° with IMU-based system (range = 96.8° to 139.5°). Similarly, in participants with SCI as in other studies [ 32 ], we found FSA values around 85.3° with the optical tracking system (range = 15.9° to 128.4°) and around 84° with the IMU-based system (range = 19.9° to 134.3°). Previous work showed that the threshold velocity for activation of the stretch reflex in participants with SCI varied between 5 and 193°/s [ 49 ].…”

“…The pendulum test is a widely used biomechanical test for evaluating knee extensor spasticity using kinematic analysis in humans with SCI [ 1 , 17 , 24 , 25 , 32 , 48 ]. The test quantifies the effect of a gravity-induced stretch of the knee extensor muscle on the leg kinematics.…”

“…Although, the pendulum test has been widely used alongside clinical scales barriers remain to implementing this exam in the clinic [ 13 , 16 , 29 , 30 ]. Over the years, the pendulum test has been instrumented using video recordings [ 22 ], electrogoniometers [ 31 , 32 ], gyroscopes [ 28 ], and accelerometers [ 33 ] making comparisons and standardization across outcomes difficult. Video recordings and systems based on optical markers are considered the gold standard for administering the pendulum test in laboratory environments but the need for markers to be visible at all times complicates physical examinations and measurements are sensitive to soft tissue artifacts and errors in markers positioning [ 34 ].…”

Pendulum test parameters are useful for detecting knee muscle hypertonia and quantifying response to an intrathecal baclofen bolus injection

“…In comparison to other pendulum parameters, F1A is the most commonly or solely used for detecting the presence and changes in quadriceps hypertonia [21,26,38–41]; however, our ROC results suggest that other parameters are just as capable, if not better, in detecting the presence of hypertonia in the knee extensors and flexors. Although some parameters seem redundant (E1A, SwingT, NoOsc), they are better viewed as complementary.…”