Quantitative clinical measure of spasticity in children with cerebral palsy

Effectiveness of a Blend of Pelvic Proprioceptive Neuromuscular Facilitation, Task-Oriented Approach, and Rood's Approach in a Three-Year-Old Child With Spastic Diplegia: A Case Report

As a result of non-progressive brain damage, cerebral palsy (CP) has traditionally been seen as a disorder of movement and posture; however, more recent classifications enable clinicians to understand more than just the movement issue. Research has evolved with the accurate categorization of cerebral palsy into distribution, motor type, and functional level. Children with spastic diplegia usually have pelvic asymmetry, which affects the child's functional abilities, including their ability to balance and walk independently. Physical therapists currently treat this illness using a variety of treatments, each of which is significant in its own way. A model for enhancing organizational capabilities is clinical management in physical therapy, which incorporates effective practices supported by research and improves outcomes. This case study demonstrates the efficiency of a deliberate physical therapy strategy to enhance functional independence in a three-year-old male child with spastic diplegia. The young patient complained of difficulties with balance and toe-walking and a delay in reaching age-appropriate milestones when seen in the neuro physiotherapy outpatient department. History demonstrated that a delayed cry occurred with an abrupt onset of fever, foaming at the mouth, and other symptoms described.

Quantifying the velocity-dependent muscle response during gait of children with Cerebral Palsy

A new method is introduced quantifying the velocity-dependent muscle response during gait in spastic muscles of children with Cerebral Palsy. The velocity-dependent muscle activation Index is calculated during a 3-dimensional gait analysis using segment angular velocity and the Instantaneous Mean Frequency calculated from surface electromyography. Typical developed children (n = 11) and children with hemiplegia (n = 11) aging from 8 to 19 years participated in the study. The rectus femoris and the medial gastrocnemius were assessed by calculating the velocity dependent muscle activation Index and the modified Ashworth Scale. Greater velocity-dependent muscle activation Index values for both medial gastrocnemius and rectus femoris muscles were associated with greater Ashworth Scale. Post hoc analysis revealed significant lower velocity-dependent muscle activation Index means in the Typical developed group compared with Ashworth Scale scores of 1, 2, 3, and 5. In addition, velocity-dependent muscle activation Index for Ashworth Scale 0, 1, and 2 were significantly lower than for Ashworth Scale 3 and 5. The velocity dependent muscle activation Index showed negative low correlation with walking speed and cadence. Findings show that spastic muscles can be quantified during dynamic functional task such as walking. Future studies should investigate the reliability of the velocity-dependent muscle activation Index that may be used for the assessment of spasticity management such as Botulinum toxin A interventions.

Biomechanical investigation of the modified Tardieu Scale in assessing knee extensor spasticity poststroke

OBJECTIVE

The modified Tardieu Scale (MTS) is a clinical tool for the measurement of muscle spasticity. The present study aimed to investigate the relationship between the MTS and the slope of the work-velocity curve as a biomechanical measure in assessing knee extensor muscle spasticity in patients with stroke.

METHODS

Thirty patients with stroke (22 female, 8 male; mean age 55.4 ± 12.0 years) participated in this study. The knee extensor spasticity was assessed with the MTS. An isokinetic dynamometer was used to move the knee passively from full extension to 90° flexion at speeds of 60°/s, 120°/s, 180°/s, and 240°/s to collect torque-angle data. The slope of the work-velocity curve was calculated using linear regression [J/(°/s)].

RESULTS

The mean of R2-R1 component of MTS was 19.73 (SD 29.85). The mean work significantly decreased as the speed increased (p < .001). The mean (SD) slope for the work-velocity curve was -0.83 (SD 0.73, range -2.6-0.3). There was no significant relationship between the R₂ -R₁ and the slope of work-velocity curve (r = 0.09, p = .62).

CONCLUSIONS

The lack of significant relationship between the MTS and the slope of work-velocity curve may question the usefulness of the MTS as a valid measure of muscle spasticity after stroke.

Stiffness of resting lumbar myofascia in healthy young subjects quantified using a handheld myotonometer and concurrently with surface electromyography monitoring

This study aimed to non-invasively quantify passive stiffness of superficial myofascia at a lower lumbar (L3-L4) anatomical level in young healthy male and female subjects and investigate its possible morphological variation. Resting prone lumbar myofascial measurements were quantified using MyotonPro(®) and statistically analyzed in 20 young healthy individuals over 3-weekly intervals, concurrently with surface electromyography (sEMG). Averaged mean ± SE stiffness (Newton/meter) over three weeks was significantly (p < 0.001) greater in males (247.8 ± 11.3) than females (208.4 ± 11.3), on the right (237.7 ± 12.8) than left sides (218.5 ± 12.3), at 10-min (231.4 ± 9.1) than initial baseline (224.8 ± 9.1) values. A polymorphism of stiffness values in 10 male and 10 female subjects was suggested by box plot analyses of the 3 weekly measurements and greater inter-individual than intra-individual variances. Greater knowledge of lumbar myofascial stiffness can improve understanding of their contributions in health and chronic low back disorders.

Dynamometer-based measure of spasticity confirms limited association between plantarflexor spasticity and walking function in persons with multiple sclerosis

The literature shows inconsistent evidence regarding the association between clinically assessed plantar-flexor (PF) spasticity and walking function in ambulatory persons with multiple sclerosis (pwMS). The use of a dynamometer-based spasticity measure (DSM) may help to clarify this association. Our cohort included 42 pwMS (27 female, 15 male; age: 42.9 +/- 10.1 yr) with mild clinical disability (Expanded Disability Status Scale score: 3.6 +/- 1.6). PF spasticity was assessed using a clinical measure, the modified Ashworth Scale (MAS), and an instrumented measure, the DSM. Walking function was assessed by the timed 25-foot walk test (T25FWT), the 6-minute walk test (6MWT), and the 12-item Multiple Sclerosis Walking Scale (MSWS-12). Spearman rho correlations were used to evaluate relationships between spasticity measures, measures of walking speed and endurance, and self-perceived limitations in walking. The correlation was small between PF spasticity and the T25FWT (PF maximum [Max] MAS rho = 0.27, PF Max DSM rho = 0.26), the 6MWT (PF Max MAS rho = -0.20, PF Max DSM rho = -0.21), and the MSWS-12 (PF Max MAS rho = 0.11, PF Max DSM rho = 0.26). Our results are similar to reports in other neurologic clinical populations, wherein spasticity has a limited association with walking dysfunction.

Effects of oral motor therapy in children with cerebral palsy

AIM

Oral motor dysfunction is a common issue in children with cerebral palsy (CP). Drooling, difficulties with sucking, swallowing, and chewing are some of the problems often seen. In this study, we aimed to research the effect of oral motor therapy on pediatric CP patients with feeding problems.

MATERIALS AND METHODS

Included in this single centered, randomized, prospective study were 81 children aged 12-42 months who had been diagnosed with CP, had oral motor dysfunction and were observed at the Pediatric Neurology outpatient clinic of the Children's Health and Diseases Department, Istanbul Medical Faculty, Istanbul University. Patients were randomized into two groups: The training group and the control group. One patient from the training group dropped out of the study because of not participating regularly. Following initial evaluation of all patients by a blinded physiotherapist and pedagogue, patients in the training group participated in 1 h oral motor training sessions with a different physiotherapist once a week for 6 months. All patients kept on routine physiotherapy by their own physiotherapists. Oral motor assessment form, functional feeding assessment (FFA) subscale of the multidisciplinary feeding profile (MFP) and the Bayley scales of infant development (BSID-II) were used to evaluate oral motor function, swallowing, chewing, the gag reflex, the asymmetrical tonic neck reflex, tongue, jaw, and mouth function, severity of drooling, aspiration, choking, independent feeding and tolerated food texture during the initial examination and 6 months later.

RESULTS

When the initial and post-therapy FFA and BSID-II scores received by patients in the training and the study group were compared, the training group showed a statistically significant improvement (P < 0.05).

CONCLUSION

Oral motor therapy has a beneficial effect on feeding problems in children with CP.

Análise isocinética da articulação do cotovelo em crianças com paralisia cerebral

A quantidade de torque aplicado na articulação é uma medida de aptidão física importante para crianças com paralisia cerebral. O presente estudo analisou parâmetros cinéticos na articulação do cotovelo em crianças saudáveis e com paralisia cerebral. Participaram 10 crianças com paralisia cerebral e 10 crianças sem comprometimento neurológico. Avaliou-se a média do pico de torque, média do ângulo do pico de torque, coeficiente de variação do torque e aceleração angular do movimento de flexo-extensão do cotovelo nas velocidades com um dinamômetro isocinético. A média de pico de torque (extensão), aceleração (flexão) e coeficiente de variação (flexão e extensão) são diferentes entre grupos. Conclui-se que o torque e aceleração sofreram interferências no movimento de flexo-extensão; as principais diferenças encontradas foram entre os extremos das velocidades; não houve diferenças no ângulo do pico de torque. A espasticidade não interferiu na força dos músculos agonistas do movimento de flexão da articulação do cotovelo.

Effects of a supported speed treadmill training exercise program on impairment and function for children with cerebral palsy

AIM

To compare the effects of a supported speed treadmill training exercise program (SSTTEP) with exercise on spasticity, strength, motor control, gait spatiotemporal parameters, gross motor skills, and physical function.

METHOD

Twenty-six children (14 males, 12 females; mean age 9y 6mo, SD 2y 2mo) with spastic cerebral palsy (CP; diplegia, n=12; triplegia, n=2; quadriplegia n=12; Gross Motor Function Classification System levels II-IV) were randomly assigned to the SSTTEP or exercise (strengthening) group. After a twice daily, 2-week induction, children continued the intervention at home 5 days a week for 10 weeks. Data collected at baseline, after 12-weeks' intervention, and 4 weeks after the intervention stopped included spasticity, motor control, and strength; gait spatiotemporal parameters; Gross Motor Function Measure (GMFM); and Pediatric Outcomes Data Collection Instrument (PODCI).

RESULTS

Gait speed, cadence, and PODCI global scores improved, with no difference between groups. No significant changes were seen in spasticity, strength, motor control, GMFM scores, or PODCI transfers and mobility. Post-hoc testing showed that gains in gait speed and PODCI global scores were maintained in the SSTTEP group after withdrawal of the intervention.

INTERPRETATION

Although our hypothesis that the SSTTEP group would have better outcomes was not supported, results are encouraging as children in both groups showed changes in function and gait. Only the SSTTEP group maintained gains after withdrawal of intervention.

Examination of the child with cerebral palsy

This article describes the balanced combination of medical history, detailed physical examination, functional assessment, imaging, observational gait analysis, computerized gait analysis, and assessment of patient and family goals that are necessary to prepare treatment plans and accurately assess outcomes of treatment of children with cerebral palsy.

Biomechanical and electromyographic assessment of spastic hypertonus in motor complete traumatic spinal cord-injured individuals

STUDY DESIGN

Between-groups design with repeated measures.

OBJECTIVE

To quantify spastic hypertonia in spinal cord-injured (SCI) individuals.

SETTING

Rehabilitative Center, Italy.

SUBJECTS

29 individuals with a motor complete SCI (American Spinal Injury Association impairment scale grade A or B) and 22 controls.

METHODS

According to the modified Ashworth scale (MAS), patients were subgrouped as SCI-1 (MAS=1, 1+) and SCI-2 (MAS=2, 3). Passive flexo-extensions of the knee were applied using an isokinetic device (LIDO Active) at 30°, 60°, 90° and 120° s(-1). We measured the peak torque, mean torque (MT) and work. Simultaneous electromyography (EMG) was recorded from leg muscles.

RESULTS

At the speed of 120° s(-1) all SCI-2 patients presented EMG reflex activities in the hamstring muscle. All biomechanical parameter values increased significantly according to speed, but analysis of variance revealed a significant interaction between the angular velocity and group (F(d.f. 6, 138) = 8.89, P < 0.0001); post hoc analysis showed significantly greater torque parameter values in the SCI-2 group compared with the SCI-1 group and the control group at 90° and 120° s(-1). Receiver operating characteristic curves showed that using peak torque values the probability of correctly classifying a patient into SCI-1 and SCI-2 was 95%, compared with 70% for MT and 68% for work.

CONCLUSIONS

The isokinetic device is useful for distinguishing individuals with a high level of spastic hypertonus. Examination of EMG activity may help ascertain whether increased muscle tone is caused by reflex hyper excitability and to determine whether muscle spasm is present. Peak torque and simultaneous EMG assessment should be considered for the evaluation of individuals with SCI in the rehabilitative context, that is, in measuring therapeutic interventions.

Evaluation of the catch in spasticity assessment in children with cerebral palsy

OBJECTIVE

To evaluate whether the catch in clinical spasticity assessment in cerebral palsy (CP) is the consequence of a sudden velocity-dependent increase in muscle activity, resulting from hyperexcitability of the stretch reflex in spasticity.

DESIGN

Cross-sectional study.

SETTING

A special school for children with physical disabilities.

PARTICIPANTS

Children with CP (N=20; age range, 5-14y; mean weight +/- SD, 35+/-14kg; mean length +/- SD, 139+/-19cm).

INTERVENTIONS

Spasticity assessment tests (using slow and fast passive stretch) were performed in the medial hamstrings, soleus, and medial gastrocnemius muscles of the children by 2 experienced examiners.

MAIN OUTCOME MEASURES

Surface electromyography (EMG) was recorded and joint motion was simultaneously measured using 2 inertial sensors. The encounter of a catch by the examiner was compared with the presence of a sudden increase in muscle activity ("burst"). The average rectified value (ARV) of the EMG signal was calculated for each test.

RESULTS

The study shows a sudden increase in muscle activity in fast passive stretch, followed by a catch (hamstrings 100%, soleus 95%, gastrocnemius 84%). The ARV in slow passive stretch was significantly lower.

CONCLUSIONS

The results confirm that in children with CP, an increase in muscle activity is primarily responsible for a catch in fast passive muscle stretch.

Age and electromyographic frequency alterations during walking in children with cerebral palsy

The use of surface electromyography (sEMG) recorded during ambulation has provided valuable insight into motor development and changes with age in the pediatric population. However, no studies have reported sEMG differences with age in the children with cerebral palsy (CP). In this study, data from 50 children were divided retrospectively into four groups, representing either an older (above the age of seven years) or younger (below the age of seven years) age group with either typical development (TD) or CP. Data were analyzed from 16 children in the younger age group with TD, and eight in the older age group with TD. Data were also available from 14 in the younger age group with CP, and 12 in the older age group with CP. SEMG signals from the rectus femoris (RF) and medial hamstring (MH) were analyzed using wavelet techniques to examine time-frequency content. RF muscle activity was statistically different between all groups (p<0.001), with an elevated instantaneous mean frequency (IMNF) in the older TD group than the younger TD group, an elevated IMNF in the younger CP group than the older CP group, and elevated IMNF in both CP groups compared to both TD groups. Activity for the MH muscle followed the same pattern except for the CP young and old group comparison, which indicated no difference. The results indicate that differences in neuromuscular activation exist between younger and older groups of children with both TD and CP, and may provide new insight into muscle activity pattern changes during the development of walking.

Knee resistance during passive stretch in patients with hypertonia

The aims of the study were to determine by a portable method (1) whether velocity-dependent changes in knee resistance in patients with spastic paresis differ from those in non-disabled subjects, and (2) whether biomechanical measures of resistance can differentiate between neural and other factors that contribute to hypertonia (increased resistance). Biomechanical (hand-hold dynamometer, electrogoniometer) and bioelectrical (EMG) measures of resistance were evaluated under static (slow stretch) and dynamic (fast stretch) conditions in twenty patients with hypertonia and 19 non-disabled subjects. Measures calculated for non-disabled subjects (control limbs) were compared to those calculated for patients (spastic limbs). Biomechanical measures of resistance did not differ strongly between groups of spastic and control limbs and between spastic limbs having different origins of knee hypertonia (neural vs. other), due to substantial variability. In contrary the static and dynamic bioelectrical measures of muscles activation were substantially larger in spastic limbs than in control limbs (p<0.05). The variability of biomechanical measures of resistance was due to varied patterns of muscle activation in response to stretch. We concluded that the biomechanical measures of hypertonia did not discriminate spastic patients from non-disabled subjects. To classify various types of knee hypertonia, the portable method should include not only analysis of biomechanical but also EMG characteristics of hypertonia. It is expected that the functional status of patients would be better predicted using clinical and quantitative measures of impairment if different classes of hypertonia (defined by different patterns of activation) were analyzed separately rather than analyzing the heterogeneous patient population as a whole.

Roles of reflex activity and co-contraction during assessments of spasticity of the knee flexor and knee extensor muscles in children with cerebral palsy and different functional levels

BACKGROUND AND PURPOSE

Spasticity is a common impairment in children with cerebral palsy (CP). The purpose of this study was to examine differences in passive resistive torque, reflex activity, coactivation, and reciprocal facilitation during assessments of the spasticity of knee flexor and knee extensor muscles in children with CP and different levels of functional ability.

SUBJECTS

Study participants were 20 children with CP and 10 children with typical development (TD). The 20 children with CP were equally divided into 2 groups: 10 children classified in Gross Motor Function Classification Scale (GMFCS) level I and 10 children classified in GMFCS level III.

METHODS

One set of 10 passive movements between 25 and 90 degrees of knee flexion and one set of 10 passive movements between 90 and 25 degrees of knee flexion were completed with an isokinetic dynamometer at 15 degrees /s, 90 degrees /s, and 180 degrees /s and concurrent surface electromyography of the vastus lateralis and medial hamstring muscles.

RESULTS

Children in the GMFCS level III group demonstrated significantly more peak knee flexor torque with passive movements at 180 degrees /s than children with TD. Children in the GMFCS level I and level III groups demonstrated significantly more repetitions with medial hamstring muscle activity, vastus lateralis muscle activity, and co-contraction than children with TD during the assessment of knee flexor spasticity at a velocity of 180 degrees /s.

DISCUSSION AND CONCLUSION

Children with CP and more impaired functional mobility may demonstrate more knee flexor spasticity and reflex activity, as measured by isokinetic dynamometry, than children with TD. However, the finding of increased reflex activity with no increase in torque in the GMFCS I group in a comparison with the TD group suggests that reflex activity may play a less prominent role in spasticity.

Reliability of Ashworth and Modified Ashworth scales in children with spastic cerebral palsy

BACKGROUND

Measurement of spasticity is a difficult and unresolved problem, partly due to its complexity and the fact that there are many factors involved. In the assessment of spasticity in the pediatric disabled population, methods that are easily used in practice are ordinal scales that still lack reliability. A prospective cross-sectional observational study was planned to determine the reliability of the Ashworth Scale (AS) and the Modified Ashworth Scale (MAS) in children with spastic cerebral palsy (CP).

METHODS

The study included 38 children with spastic diplegic CP. The mean age for the children was 52.9 months (SD: 19.6) ranging from 18 to 108 months. The functional levels of children were classified according to the Gross Motor Function Classification System. 20 children were in Level II (52.6%), 18 were in Level III (47.4%) and 9 were in Level I (23.7%). Spasticity in hip flexors, adductors, internal rotators, hamstrings, gastrocnemius were assessed by AS and MAS. Each child was assessed by three physiotherapists in two different sessions, a week apart. The intrarater reliability was determined by paired comparison of measurements for each therapist for the two assessments. Interrater reliability was determined by paired comparisons of the three therapists' measurements on the same day. The inter and intrarater reliability of the scales were evaluated by the intraclass correlation coefficient (ICC).

RESULTS

According to ICC scores, interrater reliability of AS and MAS varied from moderate to good. ICC scores of AS were between 0.54 and 0.78 and MAS were between 0.61-0.87. Test-retest results of AS and MAS varied from poor to good. ICC values were between 0.31 and 0.82 for AS and between 0.36 and 0.83 for MAS.

CONCLUSION

The interrater and intrarater reliability of AS and MAS are related to muscle and joint characters. The repetition of measurements by the same physiotherapist, and experience may not affect reliability. These scales are not very reliable and assessments of spasticity using these scales should be therefore interpreted with great caution.

Relationships Between Spasticity, Strength, Gait, and the GMFM-66 in Persons With Spastic Diplegia Cerebral Palsy

OBJECTIVE

To determine the relationships between spasticity, strength, and the functional measures of gait and gross motor function in persons with spastic diplegia cerebral palsy (CP).

DESIGN

Retrospective, cross-sectional study.

SETTING

Hospital clinic.

PARTICIPANTS

Ninety-seven participants (49 boys, 48 girls; mean age+/-standard deviation, 9.11+/-4.8 y) with spastic diplegia CP were tested once.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

A KinCom dynamometer was used to objectively measure spasticity (ankle plantarflexors, knee flexors, hip adductors) and maximum strength (ankle dorsiflexors and plantarflexors, knee flexors and extensors, hip abductors and adductors). A gait analysis was conducted to evaluate linear variables (gait speed, stride length, cadence) and kinematic variables (ankle dorsiflexion, foot progression, knee and hip flexion, pelvic tilt at initial contact and ankle dorsiflexion, knee and hip flexion, pelvic tilt, trunk rotation range of motion) during gait. Gross motor function was measured using the Gross Motor Function Measure (GMFM-66) and separately, the GMFM walking, running & jumping dimension. Multiple linear regression analysis was used to determine the relationships between spasticity, strength, gait, and the GMFM (P<.05).

RESULTS

Spasticity did not account for a substantial amount of explained variance in gait and gross motor function (up to 8% for the GMFM walking, running & jumping dimension). Moderate to high correlations existed between strength and gait linear data and function, accounting for up to 69% of the explained variance (strength and GMFM-66, r2=.69).

CONCLUSIONS

For this cohort of participants with spastic diplegia CP who ambulated with or without an assistive device, strength was highly related to function and explained far more of the variance than spasticity. The results may not be generalized to those with more severe forms of CP.

Predicting functional change from preintervention measures in selective dorsal rhizotomy

OBJECT

In this investigation the authors attempted to predict change in function following selective dorsal rhizotomy (SDR) and intensive physical therapy in patients with spastic diplegic cerebral palsy (CP) based on multidomain preintervention measures.

METHODS

Data pertaining to 22 children with CP were collected before the SDR and again 20 months afterward. Although equations for predicting change in gait speed and function (such as the Gross Motor Function Measure) were derived, the 95% confidence interval (CI) widths were too broad to make accurate predictions that were clinically useful outside the study group.

CONCLUSIONS

Future work should be focused on developing additional measures such as lower-extremity motor control and balance in an attempt to reduce the CIs to more clinically relevant values.

Effect of selective dorsal rhizotomy in the treatment of children with cerebral palsy

OBJECT

In this investigation the authors compared impairment and functional outcomes between two groups of children with cerebral palsy (CP): one group underwent selective dorsal rhizotomy (SDR) followed by intensive physical therapy (PT), and the other group underwent the latter only (PT group). Data from an age-matched group of children without disability (nondisabled [ND] group) were also collected.

METHODS

Data pertaining to the 68 children with CP were collected before any intervention and again 8 and 20 months afterwards. Data regarding the 40 children in the ND group were collected in a single session.

CONCLUSIONS

Although patients in both groups with CP were weaker than those in the ND group, they did have strength gains. Gait speed in the SDR-PT group was slower than that in the ND group preoperatively but not at 20 months postoperatively. Gait speed in the PT group remained slower than that in the ND group. The pre- to postoperative change in the Gross Motor Abilities Estimate score was significantly greater in the SDR-PT group than in the PT-only group. An effective treatment for children with CP, SDR offers gains in strength, gait speed, and overall gross motor function.

Test-retest reliability of isokinetic dynamometry for the assessment of spasticity of the knee flexors and knee extensors in children with cerebral palsy

OBJECTIVE

To assess test-retest reliability of the peak resistance torque and slope of work methods of spasticity measurement of the knee flexors and extensors in children with cerebral palsy (CP).

DESIGN

Test-retest reliability study.

SETTING

Pediatric orthopedic hospital.

PARTICIPANTS

Fifteen children with CP.

INTERVENTION

Knee extensor and flexor spasticity was assessed with an isokinetic dynamometer using passive movements at 15 degrees, 90 degrees, and 180 degrees/s taken 1 hour apart.

MAIN OUTCOME MEASURES

Peak resistive torque and work were calculated. The relative and absolute test-retest reliability was calculated by using intraclass correlation coefficients (ICCs) and Bland-Altman plots, respectively.

RESULTS

Relative reliability was good (ICC>.75) for slope-of-work and peak resistance torque measurements at a velocity of 180 degrees/s, whereas reliability of peak torque measurements was decreased (ICC<.51) at slower velocities for both muscle groups. The 95% limits of agreement of Bland-Altman plots contained most data points for both methods, but the width of the limits of agreement were wide.

CONCLUSIONS

The measurement of spasticity of the knee extensors and flexors in children with CP using peak-resistance torque at 180 degrees/s and the slope of work method has acceptable relative test-retest reliability. However, the absolute reliability of spasticity data should be considered cautiously.

Increasing ankle strength to improve gait and function in children with cerebral palsy: a pilot study

PURPOSE

This pilot study was designed to determine whether increases in ankle strength could improve gait and function in children with spastic diplegia.

METHODS

Data were obtained from 12 children with spastic diplegia who were assigned randomly to a dorsiflexor group, a plantarflexor group, a dorsi- and plantarflexor group, or a control group. Training group subjects participated in a 12-week strength program using an isokinetic dynamometer.

RESULTS

The majority of subjects increased their strength in the trained muscles; the strength of untrained muscles was unchanged. The Gross Motor Function Measure (GMFM) walk-run-jump dimension and a quality of life measure (ie, Peds QL) improved significantly for the entire training group. Gait speed was not significantly increased for the entire training group but varied among training groups. Gait kinematics significantly improved or showed trends for improvement for the entire training group.

CONCLUSION

This pilot investigation indicates that ankle strength increases may lead to improved function, gait speed, and quality of life in children with spastic diplegia.

Biomechanical assessment with electromyography of post-stroke ankle plantar flexor spasticity

Spasticity has been defined as a motor disorder characterized by a velocity-dependent increase in tonic stretch reflex (muscle tone). Muscle tone consists of mechanical-elastic characteristics, reflex muscle contraction and other elements. The aims of this study were to determine whether to assess spasticity quantitatively, and to characterize biomechanical and electromyographic spasticity assessment parameters. These assessment parameters were described by investigating the correlation between clinical measures and the response to passive sinusoidal movement with consecutive velocity increments. Twenty post-stroke hemiplegic patients and twenty normal healthy volunteers were included in the study. Five consecutive sinusoidal passive movements of the ankle were performed at specific velocities (60, 120, 180, and 240 degrees/ sec). We recorded the peak torque, work, and threshold angle using a computerized isokinetic dynamometer, and simultaneously measured the rectified integrated electromyographic activity. We compared these parameters both between groups and between different velocities. The peak torque, threshold angle, work, and rectified integrated electromyographic activity were significantly higher in the post-stroke spastic group at all angular velocities than in the normal control group. The threshold angle and integrated electromyographic activity increased significantly and linearly as angular velocity increased, but the peak torque and work were not increased in the post-stroke spastic group. Peak torque, work, and threshold angle were significantly correlated to the Modified Ashworth scale, but the integrated electromyographic activity was not. The biomechanical and electromyographic approach may be useful to quantitatively assess spasticity. However, it may also be very important to consider the different characteristics of each biomechanical parameter.

Quantitative assessment of the velocity-dependent increase in resistance to passive stretch in spastic plantarflexors

BACKGROUND

Although numerous studies revealed that isokinetic dynamometers were valuable tools for assessing spastic hypertonia, no standard methodology using such devices is currently widespread in clinical setting. The aim of this study was to standardize a protocol to assess spastic hypertonia in the triceps surae.

METHODS

The passive resistance during dorsiflexions imposed from 10 to 300 degrees /s with an isokinetic dynamometer was measured at the neutral position in 15 patients with spastic hypertonia and 12 healthy subjects. The normalized passive resistance was obtained by expressing raw passive resistance as a percent of the values measured at the lowest velocity (10 degrees /s). EMG signals from plantar and dorsiflexors were also recorded.

FINDINGS

While no significant difference between spastic patients and control subjects was observed in raw passive resistance values, the difference was significant for each tested velocity when considering the normalized values. Furthermore, the Ashworth score was significantly correlated with the normalized passive resistance for each velocity whereas no correlation was observed with the raw passive resistance. For the patients, except at the highest velocity, the normalized passive resistance was not affected by the fact that reflex responses in the triceps surae were elicited or not.

INTERPRETATION

The normalized passive resistance, expressed with respect to the initial one, i.e., measured at very low velocity, seems a very effective parameter to quantify the velocity-dependent increase in resistance to passive stretch in spastic plantarflexors. However, while the simplicity of the isokinetic tests and the reduced time of data treatment seems to support the clinical use of this methodology, further investigations are required to definitely standardize the protocol.

Differences in kinematic parameters and plantarflexor reflex responses between manual (Ashworth) and isokinetic mobilisations in spasticity assessment

OBJECTIVE

The purpose of this study was first to compare the kinematic parameters of imposed ankle mobilizations measured during Ashworth or isokinetic tests and, second, to better understand why the stretch reflex was more or less easily elicited by one method or the other.

METHODS

Passive dorsiflexions were applied on eight adult patients with plantarflexor spasticity in two conditions: (i) manually, using the Ashworth test where passive dorsiflexions were performed freely by seven rehabilitation clinicians, and (ii) instrumentally, using an isokinetic device (Cybex Norm) and a dorsiflexion velocity at 300 degrees /s. Mean values of initial ankle position, maximal angular velocity (theta;'(max)), maximal angular acceleration (theta;''(max)) and plantarflexor reflex responses obtained with each method were compared.

RESULTS

During the Ashworth test, all the patients presented reflex activities in the triceps surae while, during the isokinetic mobilization, only three out of the eight patients tested shown reflex responses. theta;'(max) values were significantly higher (P<0.05) in the manual test (308+/-80 degrees /s vs 216+/-5.5 degrees /s for the isokinetic test). The most marked difference concerned the theta;''(max) values (5046+/-2181 degrees /s(2) for the Ashworth test vs 819+/-18 degrees /s(2) for the isokinetic test, P<0.001). This parameter was significantly correlated with the mean rms-EMG values of the gastrocnemius lateralis (GL) and the soleus (SOL).

CONCLUSIONS

This study indicates that passive dorsiflexions imposed during Ashworth and isokinetic tests largely differ in velocity and acceleration, and the higher dynamic parameters evaluated during the Ashworth test could mainly explain that the stretch reflex was more easily elicited during this manual testing.

SIGNIFICANCE

If isokinetic devices offer numerous advantages in the assessment of passive resistance to spastic muscle stretch, they cannot be used to simulate the manual test.

Validation of portable muscle tone measurement device for quantifying velocity-dependent properties in elbow spasticity

The objective of this study is to develop a portable device for quantifying the velocity-dependent properties of spastic elbow muscles. Based on a motor-driven system, validation tests of the portable system such as accuracy and response of sensors were first examined. Furthermore, simulated modules (inertia, damper and spring) as well as elbow joints (15 control and 15 hemiplegic subjects) were manually stretched under four different frequencies (1/3, 1/2, 1 and 3/2 Hz) through 60 degrees range of motion. Joint resistance and displacement during sinusoidal stretch were collected for further analysis. Two quantitative parameters (i.e., viscous components under each frequency and averaged viscosity across four frequencies) were derived to estimate the velocity-dependent properties of elbow joint. Tests of simulated modules confirm the manual stretch protocol and data analysis are valid in estimating the velocity-dependent component during a sinusoidal stretch. Compared to normal control, viscous component in each stretch frequency and averaged viscosity were significantly higher in subjects with spasticity (P < 0.001). The viscous component and averaged viscosity were found highly correlated with the modified Ashworth scale. These findings suggest that measurements of viscous component and averaged viscosity during manual sinusoidal stretching using the portable device could be clinically useful in evaluating spasticity.

Biomechanic characteristics of patients with spastic and dystonic hypertonia in cerebral palsy11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated

OBJECTIVE

To determine what biomechanic characteristics of knee joint motion and walking show potential to quantitatively differentiate spasticity and dystonia in cerebral palsy (CP).

DESIGN

Descriptive measurement study.

SETTING

University hospital.

PARTICIPANTS

Seventeen pediatric and adult patients with CP.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

We measured the resistance of the knee joint at different velocities and positions, maximum muscle activation during external motion, amplitude of knee tendon reflexes, maximum isometric flexion and extension torques, velocity of walking, and knee kinematics during the gait cycle. Patients were classified into 2 groups (dystonia or spasticity) if at least 2 of 3 physicians agreed that a prominent component of dystonia was present.

RESULTS

Patients with dystonia had a greater degree of co-contraction and an increased resistance to external motion at slow velocities. The tendon reflexes were almost normal in patients with dystonia, whereas they were increased in patients with spasticity. Muscle strength was more impaired in patients with dystonia, probably as a result of greater muscle co-contraction. They also walked slower, with smaller knee ranges of motion, during the stance phase of walking.

CONCLUSIONS

The measurement of resistance and of muscle activation during passive motion and tendon reflexes shows potential to differentiate dystonia from spasticity in CP patients with a mixed form of hypertonia. More studies are needed to confirm these results.

Quantifying Active Ankle Range of Motion in Cerebral Palsy Following Selective Dorsal Rhizotomy

This study was conducted to determine whether an objective and quantitative measure for active ankle range of motion would be sensitive to differences between persons of able body and those with cerebral palsy (CP), and between pre- and postselective dorsal rhizotomy (SDR). Twelve children with spastic diplegia CP were tested before undergoing an SDR, and again after 8 months of intensive physical therapy (SDR group). Fourteen other children with spastic diplegia were tested initially and again 8 months following no intervention but maintaining their existing level of physical therapy (CP group). Twenty age-matched children of able body were tested once (AB group). A video system recorded active sagittal plane ankle movements as the seated child independently performed maximum dorsiflexion and plantarflexion. The data were tracked and analyzed to determine end-range dorsiflexion and plantarflexion, and total active ankle range of motion. Repeated-measures ANOVA and Tukey post hoc tests were used to test for significant differences among and between groups, p < 0. 05. Results for the SDR group indicated a significant increase in end-range dorsiflexion and total range of motion following the surgery, with no changes in any measures for the CP group. Results for both groups with CP indicated differences vs. the AB group. The measure provided additional information from what has previously been reported for active ankle range of motion. The integration of this measure with other objective measures for quantifying impairments and presurgical function may be useful in predicting post-SDR gait status and other functional activities.

Spastic velocity threshold constrains functional performance in cerebral palsy11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

OBJECTIVES

To evaluate a quantitative, velocity-based assessment of spasticity in the quadriceps and hamstrings muscles of children with cerebral palsy (CP) and to show the effects of spasticity in constraining knee velocities during fast gait.

DESIGN

A quantitative comparison of neuromuscular and biomechanical performance in patients with CP and controls without CP.

SETTING

Movement analysis laboratory within a university clinical referral center.

PARTICIPANTS

A convenience sample of 18 ambulatory patients with CP and 11 control subjects without CP.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Spastic threshold velocity recorded from electromyographic response during passive isovelocity knee movement was compared with knee angular velocity during fast walking, Gross Motor Function Measure (GMFM) scores, and Ashworth Scale score.

RESULTS

Patients with measurable spasticity showed slower peak knee angular velocity during walking than patients without spasticity (P<.005). A significant correlation existed between spastic threshold velocity and peak knee angular velocity during fast walking (r=.85, P<.001). Spastic threshold velocity correlated significantly with GMFM (r=.58, P<.05) but not with Ashworth score.

CONCLUSIONS

The velocity dependency of spasticity can be measured by electromyograph and dynamometer to determine spastic threshold velocity. Spastic threshold velocity correlated with limitations in joint angular velocity during walking and functional performance.

Spasticity, strength, and gait changes after surgery for cervical spondylotic myelopathy: a case report

STUDY DESIGN

A case report with repeated measures is presented.

OBJECTIVE

To describe an objective method for evaluating changes in upper- and lower-extremity spasticity and strength, as well as temporal and kinematic gait variables, after surgical intervention for cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

Degenerative cervical spinal disease is a common disorder, with some form of spondylosis demonstrated radiographically in more than 80% of those older than 55 years. Normative pre- and postoperative objective data quantifying spasticity, strength, and gait do not exist.

METHODS

A 65-year-old woman underwent C2-C3 anterior cervical discectomy and fusion for progressive myelopathy secondary to a spondylosis and disc herniation. The measure for spasticity and strength at the ankles and elbows and a gait analysis were collected before surgery and at 11 days, 3 and 6 months after surgery. Spasticity and strength were assessed using a dynamometer, and a six-camera video system was used to record the gait.

RESULTS

Preoperative left elbow flexor spasticity was more than 10 times greater than the values for the able bodies. It was reduced to normal levels after surgery. Substantial presurgery weakness was present in the elbow flexors and extensors bilaterally. Elbow extensor strength was at able-body levels after surgery. Gait speed was 57% of the able-body level before surgery and 78% of the able-body level 6 months after surgery.

CONCLUSIONS

This case study demonstrated the role of biomechanics in characterizing impairments associated with cervical spondylosis and its surgical intervention. Measures for spasticity, strength, and gait taken before and after surgery indicated a favorable outcome. This report provides a foundation for the continued use of biomechanical methods to measure changes in function and impairments associated with surgical intervention of cervical spine disorders.

A Measure of Motor Control at the Knee in Cerebral Palsy

This investigation developed a measure of motor control for the knee extensors in adults with cerebral palsy (CP). Four adults with CP and 4 able-bodied (AB) adults participated. A KinCom dynamometer rotated the knee from approximately 90º of knee flexion to 10º/s less than the participant’s maximum knee extension at a speed of 10º/s, while the participant attempted to match a 44.5-N “target” force. The average, standard deviation, and median frequency of the force-time data were used to describe the test results. The individual force values for the AB group were near the target force and clustered together. The values for the CP group were also near the target force, but displayed greater variation. The average standard deviation for the CP group was more than three times larger than that of the AB group. The average median frequency for the CP group was less than that of the AB group. Results pointed to differing strategies for each group as they attempted to match the target force. The AB group attempted to match the target force with frequent small-magnitude force changes, while the CP group attempted to match the target force with fewer oscillations of greater magnitude. The methods employed in the present investigation are initial attempts to quantify one aspect of motor control, a visually guided tracking task.

Quantifying muscle activity in non-ambulatory children with spastic cerebral palsy before and after selective dorsal rhizotomy

Cerebral palsy is a condition that results in varying degrees of functional deficits. The goal of this study was to develop an objective measure of muscle activity during a prescribed voluntary motor task in non-ambulatory children with spastic cerebral palsy. While performing a simultaneous hip/knee flexion task from the supine position, followed by return to the starting position, electromyographic and kinematic data were obtained from the right leg of eight children before and after selective dorsal rhizotomy and compared with eight age-matched controls. The electromyographic and kinematic data were combined to determine for each muscle of interest (tibialis anterior, soleus, vastus lateralis, biceps femoris) the percentage of the movement cycle for which the muscle was acting concentrically, eccentrically, isometrically or was considered inactive. Averaged over the four muscles, isometric activity decreased by 38% post-op and the time the muscles were inactive increased by 37% following surgery. The percentages of concentric and eccentric activity did not differ significantly between pre- and post-op conditions. Post-operatively, the percentage muscle activity patterns of the children with cerebral palsy more closely resembled that of the control children: averaged across all muscles and contraction types, the difference between the control children and the children with cerebral palsy was reduced by 50% following surgery. This measurement technique indicates promise as a method for quantifying muscle activity during voluntary motor tasks in non-ambulatory children with cerebral palsy.

Hip Spasticity and Strength in Children with Spastic Diplegia Cerebral Palsy

Hip spasticity and strength from 44 children with cerebral palsy (CP) and 44 children with able bodies (AB) were compared. For spasticity, a KinCom dynamometer abducted the passive hip at 4 different speeds and recorded the resistive adductor torques. Work values for the torque-angle data were calculated at each speed. Linear regression derived the slope for the line of best fit for the work-velocity data to determine the spasticity measure. For strength, the KinCom rotated the hip from maximum adduction to maximum abduction at a speed of 10°/s while the child performed a maximum abduction concentric contraction. Tests were reversed to record maximum adduction. Maximum torques and work by the abductors and adductors were calculated. Spasticity in the adductors for the CP group was significantly greater than values recorded for the AB group. All strength measures were significantly less than the AB group. Results provide objective information, quantifying hip spasticity and strength in children with CP.

Changes in ankle spasticity and strength following selective dorsal rhizotomy and physical therapy for spastic cerebral palsy

OBJECT

In this investigation the authors quantified changes in ankle plantarflexor spasticity and strength following selective dorsal rhizotomy (SDR) and intensive physical therapy in patients with cerebral palsy (CP).

METHODS

Twenty-five patients with cerebral palsy (CP group) and 12 able-bodied volunteers (AB controls) were tested with a dynamometer. For the spasticity measure, the dynamometer was used to measure the resistive torque of the plantarflexors during passive ankle dorsiflexion at five different speeds. Data were processed to yield a single value that simultaneously encompassed the three key elements associated with spasticity: velocity, resistance, and stretch. For the strength test, the dynamometer rotated the ankle from full dorsiflexion to full plantarflexion while a maximum concentric contraction of the plantarflexors was performed. Torque angle data were processed to include the work done by the patient or volunteer on the machine. Plantarflexor spasticity values for the CP group were significantly greater than similar values for the AB control group prior to surgery but not significantly different after surgery. Plantarflexor strength values of the CP group were significantly less than those of the AB control group pre- and postsurgery. Postsurgery strength values did not change relative to presurgery values.

CONCLUSIONS

The spasticity results of the present investigation agreed with those of previous studies indicating a reduction in spasticity for the CP group. The strength results did not agree with the findings of most previous related literature, which indicated that a decrease in strength should have occurred. The strength results agreed with a previous investigation in which knee flexor strength was objectively examined, indicating that strength did not decrease as a consequence of an SDR. The methods of this investigation could be used to improve SDR patient selection.

Guidance-based quantification of arm impairment following brain injury: a pilot study

This paper reports the design and preliminary testing of a device for evaluating arm impairment after brain injury. The assisted rehabilitation and measurement (ARM) Guide is capable of mechanically guiding reaching and retrieval movements across the workspace and of measuring constraint forces and range of motion during guidance. We tested the device on four hemiplegic brain-injured individuals and four unimpaired control subjects. During guided movement, the brain-injured subjects generated distinct spatial patterns of constraint force with their impaired arms that were consistent with the standard flexion and extension "synergies" described in the clinical literature. In addition, the impaired arms exhibited well-defined workspace deficits as measured by the ARM Guide. These results suggest that constraint force and range of motion measurements during mechanically guided movement may prove useful for precise monitoring of arm impairment and of the effects of treatment techniques targeted at abnormal synergies and workspace deficits.

Gait before and 10 years after rhizotomy in children with cerebral palsy spasticity

OBJECT

Selective dorsal rhizotomy is a neurosurgical procedure performed for the relief of spasticity in children with cerebral palsy, but its long-term functional efficacy is still unknown. The authors sought to address this issue by means of an objective, prospective study in which quantitative gait analysis was used.

METHODS

Eleven children with spastic diplegia (mean age at initial surgery 7.8 years) were evaluated preoperatively in 1985 and then at 1, 3, and at least 10 years after surgery. For comparison, 12 age-matched healthy individuals were also studied. Retroreflective targets were placed over the hip, knee, and ankle joints, and each individual's gait was videotaped. The video data were subsequently entered into a computer for extraction and analysis of the gait parameters. An analysis of variance yielded a significant time effect (p < 0.05), and post hoc comparisons revealed differences before and after surgery and with respect to the healthy volunteers. The knee and hip ranges of motion (59 degrees and 44 degrees, respectively, for healthy volunteers) were significantly restricted in children with spastic diplegia prior to surgery (41 degrees and 41 degrees, respectively), but were within normal limits after 10 years (52 degrees and 45 degrees, respectively). The knee and hip midrange values (31 degrees and 3 degrees, respectively, for healthy volunteers), indicative of posture, were significantly elevated preoperatively (42 degrees and 15 degrees) and increased sharply at 1 year (56 degrees and 18 degrees), but by 10 years they had decreased to within normal limits (36 degrees and 9 degrees). Step length and velocity improved postoperatively but were not within the normal range after 10 years. Ten years after surgery these patients not only had increased ranges of motion, but also used that movement at approximately a normal midrange point.

CONCLUSIONS

Selective dorsal rhizotomy is an effective method for alleviating spasticity. Furthermore, the authors provide evidence to show that lasting functional benefits, as measured by improved gait, can also be obtained.

Spasticity and strength changes as a function of selective dorsal rhizotomy

OBJECT

The goal of this investigation was to quantify changes in hamstring muscle spasticity and strength in children with cerebral palsy (CP) as a function of their having undergone a selective dorsal rhizotomy.

METHODS

Nineteen children with CP (CP group) and six children with able bodies (AB group) underwent testing with a dynamometer. For the spasticity measure, the dynamometer measured the resistive torque of the hamstring muscles during passive knee extension at four different speeds. Torque-angle data were processed to calculate the work done by the machine to extend the knee for each speed. Linear regression was used to calculate the slope of the line of best fit for the work-velocity data. The slope simultaneously encompassed three key elements associated with spasticity (velocity, resistance, and stretch) and was considered the measure of spasticity. For the strength test, the dynamometer moved the leg from full knee extension to flexion while a maximum concentric contraction of the hamstring muscles was performed. Torque-angle data were processed to calculate the work done on the machine by the child. Hamstring spasticity values for the CP group were significantly greater than similar values for the AB group prior to surgery; however, they were not significantly different after surgery. Hamstring strength values for the CP group remained significantly less than those for the AB group after surgery, but were significantly increased relative to their presurgery values.

CONCLUSIONS

The results of spasticity testing in the present investigation agreed with those of previous studies, indicating a reduction in spasticity for the CP group. The results of strength testing did not agree with those in the previous literature; a significant increase in strength was observed for the CP group.

Maximum Active Resultant Knee Joint Torques in Children with Cerebral Palsy

This investigation quantified maximum active resultant joint torques in children with spastic diplegia cerebral palsy and nondisabled children. An isokinetic dynamometer rotated the limb (10°/s) while the resultant knee joint torques (both assistive and resistive) during knee extension and flexion in 6 nondisabled children and 26 children with cerebral palsy were recorded. Torque-angle data were processed to calculate maximum values during extension and flexion and work done during the movements. An independentttest determined if significant differences existed between groups (p< .05). Maximum extensor and maximum flexor torques and work during extension and flexion were significantly less for the children with cerebral palsy. Results supported previously published research indicating that children with spastic diplegia were weaker than nondisabled children. Additional information regarding the weakness of the children with spastic diplegia near the end range of extension motion is presented.