Wartenberg pendulum test: objective quantification of muscle tone in children with spastic diplegia undergoing selective dorsal rhizotomy

Abstract

The aim of this study was to investigate the reliability and sensitivity of the Wartenberg pendulum test for quantification of muscle tone in young children with spastic diplegia undergoing selective dorsal rhizotomy (SDR). Fourteen non‐disabled children (mean age of 5.5 years, age range 2.3 to 8.8 years, one female and one male in each year) were tested twice. Twenty children with spastic diplegia (12 males, eight females; mean age of 4.3 years, age range 2.5 to 6.3 years) consecutively selected for SDR, were assessed before and 6 months after SDR. Parameters of the pendulum test: R2, R1, maximal velocity, and swing time were correlated with clinical assessments for spasticity (modified Ash worth scale, quadriceps reflex) and measurements of gross motor function: the Gross Motor Function Classification System and the Gross Motor Function Measure. The Wartenberg pendulum test was found to be an objective and sensitive method for quantifying spasticity in knee extensor muscles in children as young as 2.5 years old. The method was responsive to changes after SDR. The only correlation with clinical measurements of spasticity was between the R2 ratio and the quadriceps reflex. Swing time was the most reliable and sensitive variable; it showed a weak correlation with measurements for gross motor function.

Reliability of the three-dimensional pendulum test for able-bodied children and children diagnosed with cerebral palsy

“…In a testretest (7-14 days apart) reliability of the pendulum test performed on able-bodied children 3-8 years old reported coefficient of variance ranging from 3 to 47% for variables calculated from the pendulum test [3]. An inter-day reliability study on able-bodied adults revealed a large range in reliability with ICC ranging from 0.08 to 0.88 on 10 variables recorded using an electrogoniometer [12].…”

“…Increased tone/ spasticity of the rectus femoris, hamstrings and gastrocsoleus muscle groups are often associated with causing impaired walking and transfer abilities for children diagnosed with CP [1][2][3]. Numerous potential interventions can be used to treat spasticity in children with CP.…”

“…Two studies have reported on the repeatability of the pendulum test for able-bodied subjects [3,12]. In a testretest (7-14 days apart) reliability of the pendulum test performed on able-bodied children 3-8 years old reported coefficient of variance ranging from 3 to 47% for variables calculated from the pendulum test [3].…”

“…It is an ordinal scale based on subjective evaluation of passive resistance perceived by the examiner and to date the reliability nor validity of the MAS has been reported in children with CP [3]. The MAS may not be sensitive enough to detect small changes in spasticity [6,7].…”

“…A number studies have assessed the changes in the pendulum variables after spasticity reducing interventions such as medications [5], anesthesia [1], and rhizotomy [3]. Six months after undergoing selective dorsal rhizotomy, the mean maximum knee angular velocity during the pendulum test were significantly increased postoperatively from preoperative values in subjects diagnosed with CP [3]. Nance et al assessed the affects of tizanidine, a spasticity reducing medication that binds at the spinal and supraspinal levels, on quadriceps spasticity of 78 subjects with spinal cord injuries [13].…”