Functional Capacity in Adults With Cerebral Palsy: Lower Limb Muscle Strength Matters

Motor function and gait decline in individuals with cerebral palsy during adulthood: a narrative review of potential physiological determinants

Cerebral palsy (CP) is the most common childhood-onset disability. The evolution of gait according to severity is well known amongst children and thought to peak between 8 and 12 years of age among those walking without assistive devices. However, among adults, clinical experience as well as scientific studies report, through clinical assessments, questionnaires and interviews, increasing walking difficulties leading to an increased dependency of assistive devices in everyday ambulation. For many individuals with CP, this change will occur around 30-40 years, with the risk of losing mobility increasing with age. This narrative review aims to first provide objective evidence of motor function and gait decline in adults with CP when ageing, and then to offer mechanistic hypotheses to explain those alterations. Many studies have compared individuals with CP to the typically developing population, yet the evolution with ageing has largely been understudied. Comorbid diagnoses comprise one of the potential determinants of motor function and gait decline with ageing in people with CP, with the first manifestations happening at an early age and worsening with ageing. Similarly, ageing appears to cause alterations to the neuromuscular and cardiovascular systems at an earlier age than their typically developing (TD) peers. Future studies should, however, try to better understand how the physiological particularities of CP change with ageing that could pave the way for better strategies for maintaining function and quality of life in people with CP.

Estimates of functional muscle strength from a novel progressive lateral step-up test are feasible, reliable, and related to physical activity in children with cerebral palsy

OBJECTIVE

To determine if estimates of functional muscle strength from a novel progressive lateral-step-up test (LSUT) are feasible, reliable, and related to physical activity in children with cerebral palsy (CP).

DESIGN

Cross-sectional; test-retest reliability Subjects/Patients: Children with CP and typically developing control children (n = 45/group).

METHODS

An LSUT with 10, 15, and 20 cm step heights was completed. It was repeated 4 weeks later in 20 children with CP. A composite score of LSUT was calculated based on the step height and number of repetitions completed. Physical activity was assessed using monitors worn on the ankle and hip.

RESULTS

Only 4 (13%) of the children with CP were unable to complete a lateral step-up repetition without assistance. All children were able to complete at least 1 repetition with assistance, though more than twice as many children with CP required assistance at 15 and 20 cm step heights than at the 10 cm step height (p < 0.01). Children with CP had 59 to 63% lower LSUT performance, 37% lower physical activity assessed at the ankle, and 22% lower physical activity assessed at the hip than controls (all p < 0.01). The intra-class correlation coefficient ranged from 0.91 to 0.96 for LSUT performance at the different step heights and was 0.97 for the composite score. All LSUT performance measures were positively related to ankle physical activity in children with CP (r range = 0.43 to 0.47, all p < 0.01). Only performance at 20 cm and the composite score were positively related to hip physical activity (r = 0.33 and 0.31, respectively, both p < 0.05). The relationship between the LSUT performance and physical activity at both the ankle and hip increased when age and sex were statistically controlled (model r range = 0.55 to 0.60, all p < 0.001).

CONCLUSION

Estimates of functional muscle strength from a novel progressive LSUT are feasible, reliable, and positively related to physical activity in children with CP.

Acute passive stretching has no effect on gastrocnemius medialis stiffness in children with unilateral cerebral palsy

PURPOSE

The aim of this study was to investigate the effects of an acute high-intensity, long-duration passive stretching session of the plantar flexor muscles, on maximal dorsiflexion (DF) angle and passive stiffness at both ankle joint and gastrocnemius medialis (GM) muscle levels in children with unilateral cerebral palsy (CP).

METHODS

13 children [mean age: 10 years 6 months, gross motor function classification system (GMFCS): I] with unilateral CP underwent a 5 min passive stretching session at 80% of maximal DF angle. Changes in maximal DF angle, slack angle, passive ankle joint and GM muscle stiffness from PRE- to POST-intervention were determined during passive ankle mobilization performed on a dynamometer coupled with shear wave elastography measurements (i.e., ultrasound) of the GM muscle.

RESULTS

Maximal DF angle and maximal passive torque were increased by 6.3° (P < 0.001; + 50.4%; 95% CI 59.9, 49.9) and 4.2 Nm (P < 0.01; + 38.9%; 95% CI 47.7, 30.1), respectively. Passive ankle joint stiffness remained unchanged (P = 0.9; 0%; 95% CI 10.6, - 10.6). GM muscle shear modulus was unchanged at maximal DF angle (P = 0.1; + 34.5%; 95% CI 44.7, 24.7) and at maximal common torque (P = 0.5; - 4%; 95% CI - 3.7, - 4.3), while it was decreased at maximal common angle (P = 0.021; - 35%; 95% CI - 11.4, - 58.5). GM slack angle was shifted in a more dorsiflexed position (P = 0.02; + 20.3%; 95% CI 22.6, 18).

CONCLUSION

Increased maximal DF angle can be obtained in the paretic leg in children with unilateral CP after an acute bout of stretching using controlled parameters without changes in passive stiffness at joint and GM muscle levels.

CLINICAL TRIAL NUMBER

NCT03714269.

Systematic review: exercise training for equinus deformity in children with cerebral palsy

Background

Children with spastic cerebral palsy have motor deficits that can lead to joint contractures. Ankle equinus deformity is the most common foot deformity among children with CP. It is caused by spasticity and muscular imbalance in the gastrocnemius-soleus complex. Exercise enhances ankle function, improves gait in children with CP, and prevents permanent impairment. Therefore, there is a need to investigate the effectiveness of different types of exercise used in equine management. The aim of this review is to assess the evidence of the effectiveness of exercise training on equinus deformity in children with cerebral palsy.

Methodology

The American Academy for Cerebral Palsy and Developmental Medicine and Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology were used to conduct this systematic review. Four databases (PubMed, Cochrane Library, Physiotherapy Evidence Database (PEDro), and Google Scholar) were searched till January 2022 using predefined terms by two independent reviewers. Randomized controlled trials published in English were included. This review included seven studies with 203 participants ranging in age from 5 to 18 years. Methodological quality was assessed using AACPDM, PEDro scale; also, levels of evidence adopted from modified Sacket’s scale were used for each study. Primary outcomes were dorsiflexion angle, plantar flexion angle, and plantar flexors strength.

Results

The quality of studies ranged from good (six studies) to fair (one study). The level of evidence was level 1 (six studies) and level 2 (one study) on modified Sacket’s scale. There is a low risk of bias in the included studies. Meta-analysis revealed a non-significant difference in plantar flexor strength, plantar flexion angle, and dorsiflexion angle between the study and control group.

Conclusions

There is a need for high-quality studies to draw a clear conclusion as the current level of evidence supporting the effectiveness of various types of exercises on equinus deformity in children with cerebral palsy is still weak.

What are the optimum training parameters of progressive resistance exercise for changes in muscle function, activity and participation in people with cerebral palsy? A systematic review and meta-regression

OBJECTIVES

To explore the effect of progressive resistance exercise (PRE) on impairment, activity and participation of people with cerebral palsy (CP). Also, to determine which programme parameters provide the most beneficial effects.

DATA SOURCES

Electronic databases searched from the earliest available time.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) implementing PRE as an intervention in people with cerebral palsy were included.

STUDIES APPRAISAL & SYNTHESIS METHODS

Methodological quality of trials was assessed with the PEDro scale. Meta-analysis and meta-regression were completed.

RESULTS

We included 20 reports of 16 RCTs (n = 504 participants). Results demonstrated low certainty evidence that PRE improved muscle strength (pooled standardised mean difference (SMD)= 0.59 (95%CI: 0.16-1.01; I²=70%). This increase in muscle strength was maintained an average of 11 weeks after training stopped. Τhere was also moderate certainty evidence that it is inconclusive whether PRE has a small effect on gross motor function (SMD= 0.14 (95%CI: -0.09 to 0.36; I²=0%) or participation (SMD= 0.26 (95%CIs: -0.02 to 0.54; I²=0%). When PRE was compared with other therapy there were no between-group differences. Meta-regression demonstrated no effect of PRE intensity or training volume (frequency x total duration) on muscle strength (p > 0.5). No serious adverse events were reported. There is lack of evidence of the effectiveness of PRE in adults and non-ambulatory people with CP.

CONCLUSIONS

PRE is safe and increases muscle strength in young people with CP, which is maintained after training stops. The increase in muscle strength is unrelated to the PRE intensity or dose. CONTRIBUTION OF THE PAPER.

How Ankle Exoskeleton Assistance Affects the Mechanics of Incline Walking and Stair Ascent in Cerebral Palsy

Graded terrains, like slopes and stairs, are particularly challenging for people with neurological disorders like cerebral palsy (CP) due to increased selective muscle control and muscle strength requirements. Lower-limb exoskeletons may be able to assist individuals with CP when navigating graded terrains. This study sought to determine the effects of untethered ankle exoskeleton assistance on lower-limb joint angles, moments, and muscle activity during up-incline walking and up-stair stepping in CP (n=7). We hypothesized that powered assistance would result in improved ankle mechanics (i.e., increased total ankle moments) across both terrains. During incline walking, we found that peak ankle dorsiflexion angle increased by $7^{\mathrm{o}}$(p=0.006) during walking with ankle assistance compared to walking without the device (Shod). Compared to without the device, the peak total ankle plantarflexor moment increased by 8% (p=0.022) while peak biological ankle plantarflexor moment decreased by 17% (p< 0.001). Incline walking with ankle assistance reduced stance phase muscle activity of the soleus (20%, p=0.010) and vastus lateralis (18%, p=0.004), and swing phase tibialis activity (19%, p=0.028) compared to Shod. During stair ascent with the device, the peak total ankle plantarflexor moment increased by 17% (p=0.011) and the peak knee extensor moment increased by 40% (p=0.018) compared to Shod. These findings provide insight into the biomechanical benefits of ankle exoskeleton assistance during incline and stair walking. This work aims to advance the use of robotic assistive technology to improve mobility for people with CP.

Improving the Energy Cost of Incline Walking and Stair Ascent with Ankle Exoskeleton Assistance in Cerebral Palsy

OBJECTIVE

Many individuals with cerebral palsy (CP) experience gait deficits resulting in metabolically-inefficient ambulation that is exacerbated by graded walking terrains. The primary goal of this study was to clinically-validate the accuracy and efficacy of adaptive ankle exoskeleton assistance during steady-state incline walking and stair ascent in individuals with CP. Exploratory goals were to assess safety and feasibility of using adaptive ankle exoskeleton assistance in real-world mixed-terrain settings.

METHODS

We used a novel battery-powered ankle exoskeleton to provide adaptive ankle plantar-flexor assistance during stance phase. Seven ambulatory individuals with CP completed the study.

RESULTS

Adaptive controller accuracy was 85% for incline walking and 81% for stair-stepping relative to the biological ankle moment. Assistance improved energy cost of steady-state incline walking by 14% (p = 0.004) and stair ascent by 21% (p = 0.001) compared to walking without the device. Assistance reduced the muscular demand for the soleus and vastus lateralis during both activities. All participants were able to safely complete the real-world mixed-terrain route, with adaptive ankle assistance resulting in improved outcomes compared to walking with the device providing zero-torque; no group-level differences were found compared to walking without the device, yet individuals with more impairment exhibited a marked improvement.

CONCLUSION

Adaptive ankle exoskeleton assistance can improve the energy cost of steady-state incline walking and stair ascent in individuals with CP.

SIGNIFICANCE

As the first study to demonstrate safety and performance benefits of ankle assistance on graded terrains in CP, these findings encourage further investigation in free-living settings.

What is Known About Muscle Strength Reference Values for Adults Measured by Hand-Held Dynamometry: A Scoping Review

•

Existing literature regarding handheld dynamometer (HHD) strength reference values is scarce.

•

The current literature includes gaps relating to strength units used and well-described protocols.

•

There is a critical need to develop HHD reference values in adults.

•

Considering the increased availability of high quality HHD, this issue is urgent.

Objective

Data Sources

Study Selection

Data Extraction

Data Synthesis

Conclusion

The Contribution of Decreased Muscle Size to Muscle Weakness in Children With Spastic Cerebral Palsy

Muscle weakness is a common clinical symptom in children with spastic cerebral palsy (SCP). It is caused by impaired neural ability and altered intrinsic capacity of the muscles. To define the contribution of decreased muscle size to muscle weakness, two cohorts were recruited in this cross-sectional investigation: 53 children with SCP [median age, 8.2 (IQR, 4.1) years, 19/34 uni/bilateral] and 31 children with a typical development (TD) [median age, 9.7 (IQR, 2.9) years]. Muscle volume (MV) and muscle belly length for m. rectus femoris, semitendinosus, gastrocnemius medialis, and tibialis anterior were defined from three-dimensional freehand ultrasound acquisitions. A fixed dynamometer was used to assess maximal voluntary isometric contractions for knee extension, knee flexion, plantar flexion, and dorsiflexion from which maximal joint torque (MJT) was calculated. Selective motor control (SMC) was assessed on a 5-point scale for the children with SCP. First, the anthropometrics, strength, and muscle size parameters were compared between the cohorts. Significant differences for all muscle size and strength parameters were found (p ≤ 0.003), except for joint torque per MV for the plantar flexors. Secondly, the associations of anthropometrics, muscle size, gross motor function classification system (GMFCS) level, and SMC with MJT were investigated using univariate and stepwise multiple linear regressions. The associations of MJT with growth-related parameters like age, weight, and height appeared strongest in the TD cohort, whereas for the SCP cohort, these associations were accompanied by associations with SMC and GMFCS. The stepwise regression models resulted in ranges of explained variance in MJT from 29.3 to 66.3% in the TD cohort and from 16.8 to 60.1% in the SCP cohort. Finally, the MJT deficit observed in the SCP cohort was further investigated using the TD regression equations to estimate norm MJT based on height and potential MJT based on MV. From the total MJT deficit, 22.6–57.3% could be explained by deficits in MV. This investigation confirmed the disproportional decrease in muscle size and muscle strength around the knee and ankle joint in children with SCP, but also highlighted the large variability in the contribution of muscle size to muscle weakness.

Perceived Limitations of Walking in Individuals With Cerebral Palsy

OBJECTIVE

Impairments associated with cerebral palsy (CP) can affect gait quality and limit activity and participation. The purpose of this study was to quantify (1) which of 6 factors (pain, weakness, endurance, mental ability, safety concerns, balance) were perceived to limit walking ability the most in individuals with CP and (2) whether age or Gross Motor Function Classification System (GMFCS) level is related to that perception.

METHODS

This cross-sectional study queried data from a gait laboratory database. Perceived walking limitation was quantified using a 5-point Likert scale ("never" to "all of the time"). Included were 1566 children and adults (mean age = 10.9 y [SD = 6.8]; range = 3.0-72.1 y) with CP (GMFCS level I: 502; II: 564; III: 433; IV: 67).

RESULTS

Patients or caregivers perceived balance to limit walking ability to the greatest extent, followed by endurance, weakness, safety, mental ability, and pain. Balance was perceived to always limit walking ability in 8%, 22%, 30%, and 34% of individuals in GMFCS levels I through IV, respectively. Endurance was perceived to always limit walking ability in 5%, 13%, 13%, and 27% of individuals in GMFCS levels I through IV, respectively. There were minor differences in the perceived extent of limitation caused by the factors by GMFCS level. Only weak associations between age and pain, mental ability, safety, and balance were observed (Spearman rho = -0.13 to 0.24).

CONCLUSION

Patients or caregivers perceived decreased balance and endurance to most strongly limit walking ability. Efforts should be made to clinically track how both perceived and objective measures of these limiting factors change with age and intervention.

IMPACT

Following a patient- and family-centered care model, therapy that places greater emphasis on balance and cardiovascular endurance may have the greatest effect on walking ability for individuals with CP. Future research should quantify which therapeutic, surgical, and pharmacologic interventions minimize these impairments and optimize activity and participation.

LAY SUMMARY

Balance and endurance are perceived to be the greatest factors limiting walking in people with CP. If you have CP, your physical therapist might emphasize balance and cardiovascular endurance to improve your walking ability.

Mechanical properties of ankle joint and gastrocnemius muscle in spastic children with unilateral cerebral palsy measured with shear wave elastography

The aim of this study was to describe passive mechanical and morphological properties of the ankle joint and gastrocnemius medialis (GM) muscle in paretic and contralateral legs in highly functional children with unilateral cerebral palsy (UCP) using shear wave elastography (SWE). SWE measurements on the GM muscle were performed in both paretic and contralateral legs during passive ankle dorsiflexion using a dynamometer in 11 children (mean age: 10 years 6 months) with UCP. Torque-angle and shear modulus-angle relationships were fitted using an exponential model to determine passive ankle joint and GM muscle stiffness respectively. Based on shear-modulus-angle relationship, slack angle and shear modulus of GM muscle were compared between legs. GM and Achilles tendon length were determined at rest using ultrasonography. No significant difference was found between legs for passive ankle joint (p = 0.26; 11.2%; 95 %CI: 31.9, -9.4) and GM muscle passive stiffness (p = 0.62; -4.4%; 95 %CI: 14.7, -23.4). GM shear modulus at a common angle was significantly higher on the paretic leg (p = 0.02; +56.5%; 95 %CI: 100.5, 12.6). GM slack angle on the paretic leg was significantly shifted to a more plantarflexed position (p = 0.04; +25.5%; 95 %CI: 49.7, 1.3) and this was associated with a non-significant lower muscle length compared to the contralateral leg (p = 0.05; -4.5%; 95 %CI: -0.4, -8.7). Increased passive tension on the paretic leg when compared to the contralateral one may be explained in large part by muscle shortening. The role of altered mechanical properties remains unknown.

Increased Ankle Plantar Flexor Stiffness Is Associated With Reduced Mechanical Response to Stretch in Adults With CP

Hyperexcitable stretch reflexes are often not present despite of other signs of spasticity in people with brain lesion. Here we looked for evidence that increased resistance to length change of the plantar flexor muscle-fascicles may contribute to a reduction in the stretch reflex response in adults with cerebral palsy (CP). A total of 17 neurologically intact (NI) adults (mean age 36.1; 12 female) and 13 ambulant adults with CP (7 unilateral; mean age 33.1; 5 female) participated in the study. Subjects were seated in a chair with the examined foot attached to a foot plate, which could be moved by a computer-controlled electromotor. An ultrasound probe was placed over the medial aspect of the leg to measure the length of medial gastrocnemius muscle fascicles. Slow (7 deg/s) and fast (200 deg/s) stretches with amplitude 6 deg of the plantar flexors were applied over an ankle range of 70 deg at 10 deg intervals between 60 and 130 deg plantarflexion. It was checked by EMG electrodes that the slow stretches were sufficiently slow not to elicit any activity and that the fast stretches were sufficiently quick to elicit a maximal stretch reflex in both groups. The torque elicited by the stretches was measured together with changes in the length of medial gastrocnemius muscle fascicles. Muscle fascicles increased significantly in length with increasing dorsiflexion position in both populations (p < 0.001), but the fascicles were shorter in the CP population at all positions. Slow stretches elicited significantly larger torque and significantly smaller length change of muscle fascicles as the ankle joint position was moved more towards dorsiflexion in CP than in NI (p < 0.001). Fast stretches elicited larger torque responses at ankle joint positions of 80–100 deg in the NI than in the CP group (p < 0.01). A significant negative correlation was observed between the torque response and muscle fascicle length change to slow stretch in CP (p < 0.05), but not in NI. These findings support that increased passive resistance of the ankle plantar flexor muscle-tendon unit and development of contractures may conceal stretch reflex response in adults with CP. We argue that this should be taken into account in the neurological examination of spasticity.

Plantar flexor voluntary activation capacity, strength and function in cerebral palsy

PURPOSE

Distal lower limb motor impairment impacts gait mechanics in individuals with cerebral palsy (CP), however, the contribution of impairments of muscle activation to reduced gross motor function (GMF) is not clear. This study aimed to investigate deficits in plantar flexion voluntary activation capacity in CP compared to typically developed (TD) peers, and evaluate relationships between voluntary activation capacity, strength and GMF.

METHODS

Fifteen ambulant individuals with spastic CP (23 ± 6 years, GMFCS I-III) and 14 TD (22 ± 2 years) people participated. Plantar- and dorsiflexion strength were assessed with a dynamometer. Voluntary activation capacity was assessed using the interpolated twitch technique via single twitch supramaximal tibial nerve stimulation. GMF was assessed using the timed upstairs test, 10 m walk test, muscle power sprint test and six-minute walk test.

RESULTS

Plantar- and dorsiflexion strength were 55.6% and 60.7% lower in CP than TD (p < 0.001). Although voluntary activation capacity was 17.9% lower on average for CP than TD (p = 0.039), 46.7% of individuals with CP achieved a sufficiently high activation to fall within one standard deviation of the TD mean. Plantar flexion voluntary activation capacity did not correlate with strength (R² = 0.092, p = 0.314) or GMF measures in the high functioning CP group (GMFCS I-II).

CONCLUSION

In contrast to previous research, plantar flexion activation capacity did not strongly predict weakness or reduced GMF. We propose that muscle size contributes more to weakness than voluntary activation capacity in high functioning individuals with CP and that relationships between muscle activation and functional capacity are complicated by effects at multiple joints.

Exercise intervention protocol in children and young adults with cerebral palsy: the effects of strength, flexibility and gait training on physical performance, neuromuscular mechanisms and cardiometabolic risk factors (EXECP)

Background

Individuals with cerebral palsy (CP) have problems in everyday tasks such as walking and climbing stairs due to a combination of neuromuscular impairments such as spasticity, muscle weakness, reduced joint flexibility and poor coordination. Development of evidence-based interventions are in pivotal role in the development of better targeted rehabilitation of CP, and thus in maintaining their motor function and wellbeing. Our aim is to investigate the efficacy of an individually tailored, multifaceted exercise intervention (EXECP) in children and young adults with CP. EXECP is composed of strength, flexibility and gait training. Furthermore, this study aims to verify the short-term retention of the adaptations three months after the end of the EXECP intervention.

Methods

Twenty-four children and young adults with spastic CP will be recruited to participate in a 9-month research project with a 3-month training intervention, consisting of two to three 90-min sessions per week. In each session, strength training for the lower limbs and trunk muscles, flexibility training for the lower limbs and inclined treadmill gait training will be performed. We will evaluate muscle strength, joint flexibility, neuromuscular and cardiometabolic parameters. A nonconcurrent multiple baseline design with two pre-tests and two post-tests all interspaced by three months is used. In addition to the CP participants, 24 typically developing age and sex-matched participants will perform the two pre-tests (i.e. no intervention) to provide normative data.

Discussion

This study has a comprehensive approach examining longitudinal effects of wide variety of variables ranging from physical activity and gross motor function to sensorimotor functions of the brain and neuromuscular and cardiometabolic parameters, providing novel information about the adaptation mechanisms in cerebral palsy. To the best of our knowledge, this is the first intervention study providing supervised combined strength, flexibility and gait training for young individuals with CP.

Trial registration number

ISRCTN69044459, prospectively registered (21/04/2017).

Gene expressions in cerebral palsy subjects reveal structural and functional changes in the gastrocnemius muscle that are closely associated with passive muscle stiffness

Cerebral palsy (CP) is a non-progressive motor disorder that affects posture and gait due to contracture development. The purpose of this study is to analyze a possible relation between muscle stiffness and gene expression levels in muscle tissue of children with CP. Next-generation sequencing (NGS) of gene transcripts was carried out in muscle biopsies from gastrocnemius muscle (n = 13 children with CP and n = 13 typical developed (TD) children). Passive stiffness of the ankle plantarflexors was measured. Structural changes of the basement membranes and the sarcomere length were measured. Twelve pre-defined gene target sub-categories of muscle function, structure and metabolism showed significant differences between muscle tissue of CP and TD children. Passive stiffness was significantly correlated to gene expression levels of HSPG2 (p = 0.02; R² = 0.67), PRELP (p = 0.002; R² = 0.84), RYR3 (p = 0.04; R² = 0.66), C COL5A3 (p = 0.0007; R² = 0.88), ASPH (p = 0.002; R² = 0.82) and COL4A6 (p = 0.03; R² = 0.97). Morphological differences in the basement membrane were observed between children with CP and TD children. The sarcomere length was significantly increased in children with CP when compared with TD (p = 0.04). These findings show that gene targets in the categories: calcium handling, basement membrane and collagens, were significantly correlated to passive muscle stiffness. A Reactome pathway analysis showed that pathways involved in DNA repair, ECM proteoglycans and ion homeostasis were amongst the most upregulated pathways in CP, while pathways involved in collagen fibril crosslinking, collagen fibril assembly and collagen turnover were amongst the most downregulated pathways when compared with TD children. These results underline that contracture formation and motor impairment in CP is an interplay between multiple factors.

Reliability of functional tests of the lower limbs and core stability in children and adolescents with cerebral palsy

BACKGROUND

Muscle weakness in children and adolescents with cerebral palsy (CP) can affect daily life activities, even more if functional capabilities are poor. Also core stability plays an important role in distal force generation.

AIM

The main purpose of this study was to investigate the reliability of functional tests of the lower limbs and the core stability in children and adolescents with bilateral spastic CP with Gross Motor Function Classification System (GMFCS) levels II and III. Secondary, associations within the functional tests and between the functional tests and gait capacity were analyzed.

DESIGN

Cross sectional study.

SETTING

CP reference center *blinded for reviewers*, pediatric physiotherapists and schools for children and adolescents with motor impairments.

POPULATION

Twenty-four children and adolescents with CP (11.4±2.5 yrs, GMFCS II/III:13/11) participated in this study.

METHODS

Functional tests of the lower limbs (GMFCS II: Sit-To-Stand (STS), Lateral Step-Up (LSU), bilateral heel rise (BHR), high jump (HJ), long jump (LJ); GMFCS III: STS, LSU) and core stability (bridging and Rolling Like a Ball (RLB)) were tested twice. On the second test occasion, gait capacity (1-Minute Walk Test (1MWT) and modified Timed Up and Go (mTUG)) were also assessed.

RESULTS

Relative reliability of the functional tests ranged from good to excellent (Intraclass Correlation Coefficients (ICC), 0.88 - 0.96). Absolute reliability showed large variability with acceptable results for the BHR, HJ, LJ and RLB (Minimal Detectable Change % (MDC %) < 40%). Strong associations were found of the RLB test and the mTUG with the BHR, HJ and LJ tests.

CONCLUSIONS

The functional tests of the lower limbs and core stability were found reliable. To measure change over time, the BHR, the HJ and LJ can be used for children and adolescents with GMFCS level II. The RLB test can be used for both GMFCS levels. Associations between the BHR, HJ and LJ tests in particular showed strong associations with the RLB test and with the mTUG.

CLINICAL REHABILITATION IMPACT

this study highlighted the importance of developing functional tests for children and adolescents with lower motor function capacities and to integrate core stability tests in routine clinical assessments.

Reference Centiles to Monitor the 6-minute-walk Test in Ambulant Children with Cerebral Palsy and Identification of Effects after Rehabilitation Utilizing Whole-body Vibration

Background: Children with cerebral palsy present age-driven development in gross motor skills and walking capacity. Aims: To precisely monitor the 6-minute walk test (6MWT) in children with CP, GMFCS levels 1 and 2 over 6 months and to assess the effect of a 6-month rehabilitation program including whole-body vibration. Methods: Retrospective analysis of data of 157 children with CP who received standardized rehabilitation (DRKS00011331). 6MWT was assessed at the start (M0) and end of the training (M6), as well as at a 6-month follow-up (M12). Centiles were created using the lambda-mu-sigma (LMS) method. Results: We created 6MWT percentiles using data of all 157 children (M0 data). A medium treatment effect size (Cohen's d = 0.69) was found (M6 and M12 data). Conclusions: The generated centiles may help monitor 6MWT changes over 6 months. Combining WBV and conventional physiotherapy can significantly improve 6MWT in children with CP. Abbreviations: 6MWT: 6-Minute Walk Test; CP: Cerebral palsy; ES: effect size; GMFCS: Gross Motor Function Classification System; GMFM-66: Gross Motor Function Measure 66; LOESS: locally weighted scatterplot smoothing; LMS: lambda-mu-sigma; MCID: minimal clinical important difference; SD: standard deviation; SRM: standardized response mean; WBV: whole-body vibration.

Progressive resistance training for adolescents with cerebral palsy: the STAR randomized controlled trial

AIM

To evaluate the effect of progressive resistance training of the ankle plantarflexors on gait efficiency, activity, and participation in adolescents with cerebral palsy (CP).

METHOD

Sixty-four adolescents (10-19y; 27 females, 37 males; Gross Motor Function Classification System [GMFCS] levels I-III) were randomized to 30 sessions of resistance training (10 supervised and 20 unsupervised home sessions) over 10 weeks or usual care. The primary outcome was gait efficiency indicated by net nondimensional oxygen cost (NNcost). Secondary outcomes included physical activity, gross motor function, participation, muscle strength, muscle and tendon size, and muscle and tendon stiffness. Analysis was intention-to-treat.

RESULTS

Median attendance at the 10 supervised sessions was 80% (range 40-100%). There was no between-group difference in NNcost at 10 (mean difference: 0.02, 95% confidence interval [CI] -0.07 to 0.11, p=0.696) or 22 weeks (mean difference: -0.08, 95% CI -0.18 to 0.03, p=0.158). There was also no evidence of between-group differences in secondary outcomes at 10 or 22 weeks. There were 123 adverse events reported by 27 participants in the resistance training group.

INTERPRETATION

We found that 10 supervised sessions and 20 home sessions of progressive resistance training of the ankle plantarflexors did not improve gait efficiency, muscle strength, activity, participation, or any biomechanical outcome among adolescents with CP.

WHAT THIS PAPER ADDS

Thirty sessions of progressive resistance training of the ankle plantarflexors over 10 weeks did not improve gait efficiency among ambulatory adolescents with cerebral palsy. Resistance training did not improve muscle strength, activity, or participation. Ninety percent of participants experienced an adverse event. Most adverse events were expected and no serious adverse events were reported.

Multi-frequency bioimpedance: a non-invasive tool for muscle-health assessment of adults with cerebral palsy

Muscle contracture development is a major complication for individuals with cerebral palsy (CP) and has lifelong implications. In order to recognize contracture development early and to follow up on preventive interventions aimed at muscle health development, non-invasive, and easy to use methods are needed. The aim of the present study was to assess whether multi-frequency Bioimpedance (mfBIA) can be used to detect differences between skeletal muscle of individuals with CP and healthy controls. The mfBIA technique was applied to the medial gastrocnemius muscle of n = 24 adults with CP and n = 20 healthy controls of both genders. The phase angle (PA) and the centre frequency (fc) were significantly lower in individuals with CP when compared to controls; PA: - 25% for women and - 31.8% for men (P < 0.0001); fc: - 5.6% for women and - 5.2% for men (P < 0.009). The reactance (Xc) and the extracellular resistance (Re) of skeletal muscle from individuals with CP were significantly higher when compared to controls; Xc: + 9.9% for women and + 28.9% for men (P < 0.0001); Re: + 39.7% for women and + 91.2% for men (P < 0.0001). The present study shows that several mfBIA parameters differ significantly between individuals with CP and healthy controls. Furthermore, these changes correlated significantly with the severity of CP, as assessed using the GMFCS scale. The present data indicate that mfBIA shows promise in terms of being a useful diagnostic tool, capable of characterizing muscle health and its development in individuals with cerebral palsy.

Epidemiology of Cerebral Palsy in Adulthood: A Systematic Review and Meta-analysis of the Most Frequently Studied Outcomes

OBJECTIVE

To describe the epidemiology of health status, impairments, activities and participation in adults with cerebral palsy (CP).

DATA SOURCES

Embase, MEDLINE, Web of Science, PsycINFO, Cumulative Index to Nursing and Allied Health, Cochrane, and Google Scholar were searched for 3 themes ("cerebral palsy," "adult," and "outcome assessment") in literature published between January 2000 and December 2018.

STUDY SELECTION

Full-article peer-reviewed English journal articles on descriptive, observational, or experimental studies describing the most studied outcomes in adults with CP (n≥25, age≥18y) were included. Studies were included in the analyses if frequently studied outcomes were described in at least 3 studies using similar methods of assessment.

DATA EXTRACTION

Data were extracted independently by 2 authors from 65 articles (total N=28,429) using a standardized score sheet.

DATA SYNTHESIS

Meta-analyses revealed that overall, on average 65.1% (95% confidence interval [CI], 55.1-74.5) of adults with CP experienced pain, 57.9% (95% CI, 51.1-64.6) were ambulant, 65.5% (95% CI, 61.2-69.7) had little or no limitation in manual ability, 18.2% (95% CI, 10.6-27.2) had tertiary education, 39.2% (95% CI, 31.5;47.1) were employed, and 29.3% (95% CI, 9.0-55.3) lived independently. In adults without intellectual disability, proportions of individuals who were ambulant (72.6% [95% CI, 58.8-84.5]) and lived independently (90.0% [95% CI, 83.8-94.9]) were higher (P=.014 and P<.01, respectively). The Fatigue Severity Scale score was 4.1 (95% CI, 3.8-4.4). Epilepsy (28.8% [95% CI, 20.1-38.4]) and asthma (28.3% [95% CI, 18.7-38.9]) were especially prevalent comorbidities.

CONCLUSIONS

The present systematic review and meta-analysis on the epidemiology of adults with CP provided state-of-the-art knowledge on the most frequently studied outcomes. On average, adults with CP are fatigued, and a majority experience pain, are ambulant, and have little or no difficulty with manual ability. On average, 40% are employed and 30% live independently. More uniformity in assessment and reports is advised to improve knowledge on epidemiology and gain insight in more outcomes.

Gait training facilitates push-off and improves gait symmetry in children with cerebral palsy

BACKGROUND

Human walking involves a rapid and powerful contraction of ankle plantar flexors during push-off in late stance.

OBJECTIVE

Here we investigated whether impaired push-off force contributes to gait problems in children with cerebral palsy (CP) and whether it may be improved by intensive gait training.

METHODS

Sixteen children with CP (6-15 years) and fourteen typically developing (TD) children (4-15 years) were recruited. Foot pressure was measured by insoles and gait kinematics were recorded by 3-dimensional video analysis during treadmill and overground walking. The peak derivative of ground reaction force at push off (dPF) was calculated from the foot pressure measurements. Maximal voluntary plantar flexion (MVC) was measured while seated. Measurements were performed before and after a control period and after 4 weeks of 30 minutes daily inclined treadmill training.

RESULTS

dPF and MVC were significantly lower in children with CP on the most affected (MA) as compared to TD children (p < .001). dPF was lower on the MA leg as compared to the less affected (LA) leg in children with CP (p < .05). Following gait training, increases in dPF (p < .001) and MVC (p < .01) were observed for the MA leg. Following gait training children with CP showed similar timing of dPF and similar stance phase duration on both legs indicating improved symmetry of gait. These effects were also shown during overground walking.

CONCLUSION

Impaired ability to voluntarily activate ankle plantar flexors and produce a rapid and powerful push-off during late stance are of importance for impaired gait function in children with CP. Intensive treadmill training may facilitate the drive to ankle plantar flexors and reduce gait asymmetry during both treadmill and overground walking.

The effect of combined functional anaerobic and strength training on treadmill gait kinematics and kinetics in ambulatory young adults with cerebral palsy

BACKGROUND

Leg muscle weakness is a major impairment for individuals with cerebral palsy (CP) and is related to reduced functional capacity. Evidence is limited regarding the translation of strength improvements following conventional resistance training to improved gait outcomes.

RESEARCH QUESTION

Does a combined functional anaerobic and lower limb strength training intervention improve gait kinematics and kinetics in individuals with CP aged 15-30 years? 17 young adults (21 ± 4 years, 9 males, GMFCS I = 11, II = 6) were randomized to 12 weeks, 3 sessions per week, of high intensity functional anaerobic and progressive resistance training of the lower limbs (n = 8), or a waitlist control group (n = 9). Pre- and post-training outcomes included maximum ankle dorsiflexion angle at foot contact and during stance, gait profile score, ankle and hip power generation during late stance, and the ratio of ankle to hip power generation.

RESULTS

There were no between-group differences after the intervention for any kinematic or kinetic gait outcome variable. Within-group analysis revealed an increase in peak ankle power during late stance (0.31 ± 0.28 W·kg^-1, p = 0.043) and ankle to hip power ratio (0.43 ± 0.37, p = 0.034) following training in the intervention group.

SIGNIFICANCE

We have previously reported increased overground walking capacity, agility and sprint power, in the training group compared to the control group at 12-weeks. These changes in overground measures of functional capacity occurred in the absence of changes in treadmill gait kinematics and kinetics reported here.

ANZCTR

12614001217695.