Assessment of Muscle Endurance of the Knee Extensor Muscles in Adolescents With Spastic Cerebral Palsy Using a Submaximal Repetitions-to-Fatigue Protocol

doi:10.1016/j.apmr.2014.05.010

Archives of Physical Medicine and Rehabilitation

Volume 95, Issue 10, October 2014, Pages 1888-1894

https://doi.org/10.1016/j.apmr.2014.05.010 Get rights and content

Abstract

Objective

To compare muscle endurance in adolescents with spastic cerebral palsy (CP) with typically developing (TD) peers using a submaximal repetitions-to-fatigue (RTF) protocol.

Design

Cross sectional.

Setting

Human motion laboratory.

Participants

Adolescents with spastic CP (n=16; Gross Motor Function Classification System levels I or II) and TD adolescents (n=18) within the age range of 12 to 19 years old.

Interventions

Not applicable.

Main Outcome Measures

Each participant performed 3 RTF tests at different submaximal loads, ranging from 50% to 90% of their maximal voluntary knee extension torque. The relation between the number of repetitions (repetition maximum [RM]) and imposed submaximal relative (percent of maximal voluntary torque [%MVT]) and absolute (Nm/kg) torque was quantified. To compare adolescents with CP with TD adolescents, a mixed linear model was used to construct load endurance curves. Surface electromyography of quadriceps muscles was measured to assess changes in normalized amplitude and median frequency (MF) as physiological indicators of muscle fatigue.

Results

Adolescents with CP showed a larger decrease in %MVT per RM than TD adolescents (P<.05). TD adolescents showed substantial higher absolute (Nm/kg) load endurance curves than adolescents with CP (P<.001), but they did not show a difference in slope. Electromyographic normalized amplitude increased significantly (P<.05) in the quadriceps muscles in all tests for both groups. Electromyographic MF decreased significantly (P<.05) in tests with the low and medium loads. Electromyographic responses did not differ between groups, indicating that similar levels of muscle fatigue were reached.

Conclusions

Adolescents with CP show slightly lower muscle endurance compared with TD adolescents on a submaximal RTF protocol, which is in contrast with earlier findings in a maximal voluntary fatigue protocol. Accordingly, adolescents with CP have a reduced capacity to endure activities at similar relative loads compared with TD adolescents.

Section snippets

Study design and setting

This cross-sectional observational study was performed in 2 rehabilitation settings (VU University Medical Center, Amsterdam; Rehabilitation Center Heliomare, Wijk aan Zee). Approval was provided by the ethical committee. All subjects signed informed consent. In addition, all parents or legal guardians of adolescents under 18 years old signed the informed consent.

Participants

Sixteen adolescents with spastic CP and 18 TD adolescents within the age range of 12 to 19 years old were recruited for the study.

Participants

Table 1 presents the participants' characteristics. Boys and girls were equally distributed over the groups (χ²=.169, P=.681). TD adolescents were significantly taller than the adolescents with CP (P<.05). The remaining characteristics did not differ between the groups. Analysis showed significantly lower knee extension torque (MVT) for adolescents with CP compared with the preferred leg of TD adolescents (t=4.313, P<.01).

RTF tests

A typical example of RTF tests of a TD adolescent is shown in figure 1.

Discussion

This study aimed to compare muscle endurance in adolescents with spastic CP and TD adolescents using a submaximal RTF protocol. An important finding from this investigation is that the relative load endurance curve of adolescents with CP at high-load conditions (>50% MVT) showed a slightly steeper slope than TD adolescents. With an increase of the RM, adolescents with CP showed a somewhat larger decrease in relative (%MVT) load than the TD adolescents. On the basis of this finding, the muscle

Conclusions

In contrast with previous studies,5, 6 our submaximal RTF protocol demonstrates that adolescents with CP show slightly lower muscle endurance in comparison with TD adolescents. Accordingly, adolescents with CP have somewhat reduced capacity to endure activities at similar relative loads compared with TD adolescents. As becomes apparent from the absolute load endurance curve, adolescents with CP have a considerably reduced ability to sustain submaximal absolute loads, similar to those challenged

Suppliers

a.
HUMAC NORM; Lode, Zernikepark 16, 9747 AN Groningen, The Netherlands.
b.
Biodex Medical Systems Inc, 20 Ramsey Rd, Shirley, NY 11967.
c.
TMSi, Zutphenstraat 57, 7575 EJ Oldenzaal, The Netherlands.
d.
AURION, Viale Certosa 191, 20151 Milano, Italy.
e.
Mathworks Inc, 3 Apple Hill Dr, Natick, MA 01760-2098.
f.
IBM Corp, 1 New Orchard Rd, Armonk, NY 10504-1722.

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Cited by (16)

Energetics of walking in individuals with cerebral palsy and typical development, across severity and age: A systematic review and meta-analysis
2021, Gait and Posture
Citation Excerpt :
This reduced force-generating capacity of the muscle in individuals with CP might result with high relative demand of lower limb skeletal muscles during walking, making these individuals more prone to fatigue. These results are consistent with findings showing lower muscle endurance in quadriceps muscles of CP undergoing a submaximal repetition-to-fatigue protocol compared to control subjects [103]. In addition, it has been recently shown that the decrease of EMG median frequency and increase of EMG amplitude in lower leg muscles were larger in children with CP compared to typically developing peers during overground walking at self-selected speed [15].
Individuals with cerebral palsy (CP) report physical fatigue as a main cause of limitation, deterioration and eventually cessation of their walking ability. A consequence of higher level of fatigue in individuals with CP leads to a less efficient and long-distance walking ability.
This systematic review investigates the difference in 1) walking energy expenditure between individuals with CP and age-matched typically developing (TD) individuals; and 2) energetics of walking across Gross Motor Function Classification System (GMFCS) levels and age.
Five electronic databases (PubMed, Web of Science, CINAHL, ScienceDirect and Scopus) were searched using search terms related to CP and energetics of walking.
Forty-one studies met inclusion criteria. Thirty-one studies compared energy expenditure between CP and age-matched controls. Twelve studies correlated energy expenditure and oxygen cost across GMFCS levels. Three studies investigated the walking efficiency across different ages or over a time period. A significant increase of energy expenditure and oxygen cost was found in individuals with CP compared to TD age-matched individuals, with a strong relationship across GMFCS levels.
Despite significant differences between individuals with CP compared to TD peers, variability in methods and testing protocols may play a confounding role. Analysis suggests oxygen cost being the preferred/unbiased physiological parameter to assess walking efficacy in CP. To date, there is a knowledge gap on age-related changes of walking efficiency across GMFCS levels and wider span of age ranges. Further systematic research looking at longitudinal age-related changes of energetics of walking in this population is warranted.
Plantar flexor muscle weakness and fatigue in spastic cerebral palsy patients
2017, Research in Developmental Disabilities
Citation Excerpt :
Similarly, discrepant results have been found for the knee flexors (Eken et al., 2013; Moreau et al., 2016; Moreau et al., 2008). In contrast, some studies found patients with CP to be less fatigue resistant than their peers when EMG activity (Eken et al., 2014) or time-to-task failure (Eken et al., 2013; Leunkeu et al., 2010) were used, while some other studies found a similar fatigue resistance in the two populations with these same fatigue indexes (Eken et al., 2014; Leunkeu et al., 2010; Moreau et al., 2016). Overall, these results show that when force output is used to monitor fatigue development, a similar or lower fatigue level is observed in patients with CP in comparison to their peers, whereas discrepant results are observed when EMG activity is used (Table 3).
Patients with cerebral palsy develop an important muscle weakness which might affect the aetiology and extent of exercise-induced neuromuscular fatigue.
This study evaluated the aetiology and extent of plantar flexor neuromuscular fatigue in patients with cerebral palsy.
Ten patients with cerebral palsy and 10 age- and sex-matched healthy individuals (∼20 years old, 6 females) performed four 30-s maximal isometric plantar flexions interspaced by a resting period of 2–3 s to elicit a resting twitch. Maximal voluntary contraction force, voluntary activation level and peak twitch were quantified before and immediately after the fatiguing task.
Before fatigue, patients with cerebral palsy were weaker than healthy individuals (341 ± 134 N vs. 858 ± 151 N, p < 0.05) and presented lower voluntary activation (73 ± 19% vs. 90 ± 9%, p < 0.05) and peak twitch (100 ± 28 N vs. 199 ± 33 N, p < 0.05). Maximal voluntary contraction force was not significantly reduced in patients with cerebral palsy following the fatiguing task (−10 ± 23%, p > 0.05), whereas it decreased by 30 ± 12% (p < 0.05) in healthy individuals.
Plantar flexor muscles of patients with cerebral palsy were weaker than their healthy peers but showed greater fatigue resistance.
Cerebral palsy is a widely defined pathology that is known to result in muscle weakness. The extent and origin of muscle weakness were the topic of several previous investigations; however some discrepant results were reported in the literature regarding how it might affect the development of exercise-induced neuromuscular fatigue. Importantly, most of the studies interested in the assessment of fatigue in patients with cerebral palsy did so with general questionnaires and reported increased levels of fatigue. Yet, exercise-induced neuromuscular fatigue was quantified in just a few studies and it was found that young patients with cerebral palsy might be more fatigue resistant that their peers. Thus, it appears that (i) conflicting results exist regarding objectively-evaluated fatigue in patients with cerebral palsy and (ii) the mechanisms underlying this muscle fatigue − in comparison to those of healthy peers − remain poorly understood. The present study adds important knowledge to the field as it shows that when young adults with cerebral palsy perform sustained maximal isometric plantar flexions, they appear less fatigable than healthy peers. This difference can be ascribed to a better preservation of the neural drive to the muscle. We suggest that the inability to drive their muscles maximally accounts for the lower extent of exercise-induced neuromuscular fatigue in patients with cerebral palsy.
Children With Cerebral Palsy Show Higher Static - But Not Higher Dynamic - Motor Fatigability in Grip and Pinch Tasks Than Children With Typical Development Do
2023, Physical Therapy
Lower limb muscle fatigue after uphill walking in children with unilateral spastic cerebral palsy
2022, PLoS ONE
Multimedia Teaching System Based on Art Interaction Technology
2022, Computer Science and Information Systems
Progress in the application of whole-body vibration on the rehabilitation of children with cerebral palsy
2021, Zhongguo Ertong Baojian Zazhi

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: Supported by the Revalidatiefonds (grant no. R2010142) and JohannaKinderFonds and Kinderfonds Adriaanstichting (grant no. 2011-044).

: Disclosures: none.

View full text

Original articleAssessment of Muscle Endurance of the Knee Extensor Muscles in Adolescents With Spastic Cerebral Palsy Using a Submaximal Repetitions-to-Fatigue Protocol

Abstract

Objective

Design

Setting

Participants

Interventions

Main Outcome Measures

Results

Conclusions

Section snippets

Study design and setting

Participants

Participants

RTF tests

Discussion

Conclusions

Suppliers

Eur J Paediatr Neurol

Gait Posture

Arch Phys Med Rehabil

Neuropsychologia

J Electromyogr Kinesiol

Proposed definition and classification of cerebral palsy

Dev Med Child Neurol

Fatigue in adults with cerebral palsy in Norway compared with the general population

Dev Med Child Neurol

Ambulatory capacity in cerebral palsy: prognostic criteria and consequences for intervention

Dev Med Child Neurol

Contractile speed and EMG changes during fatigue of sustained maximal voluntary contractions

J Neurophysiol

Cardiopulmonary exercise data during quadriceps isometric contraction sustained to fatigue in children with cerebral palsy

Isokinet Exerc Sci

Relative muscular endurance performance as a predictor of bench press strength in college men and women

J Appl Sport Sci Res

Voluntary muscle activation, contractile properties, and fatigability in children with and without cerebral palsy

Muscle Nerve

Original article
Assessment of Muscle Endurance of the Knee Extensor Muscles in Adolescents With Spastic Cerebral Palsy Using a Submaximal Repetitions-to-Fatigue Protocol