How much trunk control is affected in adults with moderate-to-severe cerebral palsy?

Trunk postural control during unstable sitting among individuals with and without low back pain: A systematic review with an individual participant data meta-analysis

INTRODUCTION

Sitting on an unstable surface is a common paradigm to investigate trunk postural control among individuals with low back pain (LBP), by minimizing the influence lower extremities on balance control. Outcomes of many small studies are inconsistent (e.g., some find differences between groups while others do not), potentially due to confounding factors such as age, sex, body mass index [BMI], or clinical presentations. We conducted a systematic review with an individual participant data (IPD) meta-analysis to investigate whether trunk postural control differs between those with and without LBP, and whether the difference between groups is impacted by vision and potential confounding factors.

METHODS

We completed this review according to PRISMA-IPD guidelines. The literature was screened (up to 7th September 2023) from five electronic databases: MEDLINE, CINAHL, Embase, Scopus, and Web of Science Core Collection. Outcome measures were extracted that describe unstable seat movements, specifically centre of pressure or seat angle. Our main analyses included: 1) a two-stage IPD meta-analysis to assess the difference between groups and their interaction with age, sex, BMI, and vision on trunk postural control; 2) and a two-stage IPD meta-regression to determine the effects of LBP clinical features (pain intensity, disability, pain catastrophizing, and fear-avoidance beliefs) on trunk postural control.

RESULTS

Forty studies (1,821 participants) were included for the descriptive analysis and 24 studies (1,050 participants) were included for the IPD analysis. IPD meta-analyses revealed three main findings: (a) trunk postural control was worse (higher root mean square displacement [RMSdispl], range, and long-term diffusion; lower mean power frequency) among individuals with than without LBP; (b) trunk postural control deteriorated more (higher RMSdispl, short- and long-term diffusion) among individuals with than without LBP when vision was removed; and (c) older age and higher BMI had greater adverse impacts on trunk postural control (higher short-term diffusion; longer time and distance coordinates of the critical point) among individuals with than without LBP. IPD meta-regressions indicated no associations between the limited LBP clinical features that could be considered and trunk postural control.

CONCLUSION

Trunk postural control appears to be inferior among individuals with LBP, which was indicated by increased seat movements and some evidence of trunk stiffening. These findings are likely explained by delayed or less accurate corrective responses.

SYSTEMATIC REVIEW REGISTRATION

This review has been registered in PROSPERO (registration number: CRD42021124658).

What Is the Relationship between Trunk Control Function and Arm Coordination in Adults with Severe-to-Moderate Quadriplegic Cerebral Palsy?

Adults with tetraparesis cerebral palsy (i.e., wheelchair users) tend to experience more accelerated ageing, resulting in physical deterioration that increases the impact of the disability, leading to a loss of mobility that interferes with people's daily activities and participation in the community. The aim of this work is to study the relationship between trunk control and the function of the less-affected arm in this population. For this purpose, 41 para-athletes were invited to participate in this study, performing five tests to assess upper limb coordination, two tests to assess manual dexterity [i.e., Box and Block Test (BBT) and Box and Ball Test (BBLT)] and three tests to assess intra-limb coordination in different planes. Trunk control was assessed in both static and dynamic sitting conditions. The results show moderate correlations between static postural control and manual dexterity tests in the BBT (r = -0.553; p = 0.002) and BBLT (r = -0.537; p = 0.004). Large correlations were also found between static postural control and intra-limb tasks in horizontal (r = 0.769; p = 0.001) and vertical movements (r = 0.739; p = 0.009). Better static trunk control is related to a better upper limb function in the sagittal plane. Considerations and implications are explained in the manuscript.

Objective measurement of sitting - Application in children with cerebral palsy

BACKGROUND

Children with cerebral palsy (CP) and a severe motor impairment, have limited ability to perform volitional movements due to spasticity, involuntary postures and movements and reduced ability to maintain antigravity head and trunk control. A stable sitting position is a prerequisite for participation in daily life, but there is a lack of objective measurement methods for this population.

RESEARCH QUESTION

Is it feasible to measure a stable sitting position with pressure mapping and 2D motion analysis, and can it detect differences to a) a reference group, b) between subgroups of CP and c) before and after treatment with intrathecal baclofen (ITB)?

METHODS

Pressure mapping, and a 2D motion analysis system, were used to capture movements of centre of pressure (CoP), and movements of head, hand and leg, sitting on a bench for 90 s. Twenty-two children with dyskinetic or bilateral spastic CP, GMFCS III-V, mean age 9.0, and 30 children with typical development (TD) mean age 10.7, were recruited between 2010 and 2019. Seventeen children were treated with ITB. Parents were interviewed regarding aspect of sitting. Non-parametric methods were used for statistical analysis.

RESULTS

Differences in CoP and kinematics were detected with more movements in children with CP compared to children with TD (p < 0.001). There were more movements in children with dyskinetic CP compared to children with bilateral spastic CP as captured with the pressure mapping system (CoP distance p = .005 and Anterio-Posterior sway p = .014). After treatment with ITB, involuntary movements had decreased (CoP p = 0.006-0.035, kinematics p = 0.002-0.020). Parents reported improvement in sitting. The two measurement systems showed consistent results (rho 0.500-0.771, p = <0.001-0.049).

SIGNIFICANCE

It was feasible to objectively measure sitting position in children with a moderate-to-severe motor impairment with differences to a reference group and after an intervention. CoP and head movements were the variables that were easiest to capture.

Establishing the reliability of instrumented trunk impairment assessment methods to enable evidence-based classification in Para swimming

This study examined the reliability of instrumented trunk assessment methods across two experiments to develop and improve evidence-based classification in Para swimming. Trunk coordination, range of motion (ROM), and strength were assessed in 38 non-disabled participants. Each test battery was completed on two occasions to determine inter-session reliability. Intra-session reliability was also determined in Experiment Two. Absolute agreement of two-way mixed intraclass correlation coefficients (ICC 3,1) was calculated to assess reliability. Standard errors of measurement (SEMs) were also reported to facilitate comparisons between different outcomes. Trunk coordination measures had low-to-moderate reliability (inter-session ICCs = 0.00-0.60; intra-session ICCs = 0.14-0.65) and variable SEMs (5-60%). Trunk ROM demonstrated moderate-to-excellent reliability (inter-session ICCs = 0.61-0.93; intra-session ICCs = 0.87-0.95) and good SEMs (<10%). Trunk strength measures demonstrated good-to-excellent reliability (ICCs = 0.87-0.98) and good SEMs (<10%). The strength values obtained for the load cell and hand-held dynamometer (HHD) were significantly different from each other with the HHD underestimating strength. Modifications provided in Experiment Two improved the reliability of strength and ROM assessments but did not improve coordination measures. Further research involving para swimmers is required to establish the validity of the methods.

The Validity, Reliability, and Sensitivity of a Smartphone-Based Seated Postural Control Assessment in Wheelchair Users: A Pilot Study

Seated postural control is essential for wheelchair users to maintain proper position while performing activities of daily living. Clinical tests are commonly used to measure seated postural control, yet they are subjective and lack sensitivity. Lab-based measures are highly sensitive but are limited in scope and restricted to research settings. Establishing a valid, reliable, and accessible measurement tool of seated postural control is necessary for remote, objective assessments. Therefore, the purpose of this study was to examine the validity, reliability, and sensitivity of smartphone-based postural control assessments in wheelchair users. Eleven participants (age: 35.4 ± 17.9) completed two experimental visits 1-week apart consisting of three clinical tests: Trunk Control Test (TCT), Function in Sitting Test (FIST), and Tee-shirt Test, as well as, standardized instrumented balance tasks that manipulated vision (eyes open and closed), and trunk movement (functional reach and stability boundary). During these tasks, participants held a smartphone instrumented with a research-grade accelerometer to their chest. Maximum and root mean square (RMS) acceleration in the medial-lateral (ML) and anterior-posterior (AP) axes were derived. Participants were grouped into non-impaired and impaired postural groups based on FIST scores. Spearman rank-order correlations were conducted between the two devices' outcome measurements and between these measures and those of the clinical tests. Receiver operating characteristic (ROC) curves and the area under the curves (AUC) were determined to distinguish participants with and without impaired postural control. The reliability of outcome variables was assessed using inter-class correlations. Strong correlations between outputs derived from the smartphone and research-grade accelerometer were seen across balance tasks (ρ = −0.75–1.00; p ≤ 0.01). Numerous significant moderate correlations between clinical test outcomes and smartphone and research-grade RMS ML accelerometry were seen (ρ = −0.62 to 0.83 (p ≤ 0.044)]. On both devices, the AUC for ROC plots were significant for RMS ML sway during the eyes open task and functional stability boundary (p < 0.05). Reliability of smartphone accelerometry was comparable to the research-grade accelerometer and clinical tests. This pilot study illustrated that smartphone-based accelerometry may be able to provide a valid and reliable assessment of seated postural control and have the ability to distinguish between those with and without impaired postural control.

Inter-Rater Reliability, Concurrent Validity and Sensitivity of Current Methods to Assess Trunk Function in Boccia Player with Cerebral Palsy

Trunk function is a core factor to allocate Boccia players with cerebral palsy in BC1 and BC2 sport classes, according to the Boccia International Sports Federation (BISFed). However, the appropriateness of the current test to assess trunk function has never been studied to determine its reliability, validity and sensitivity to discriminate between different levels of impairment. Thirty-six players (BC1 = 13 and BC2 = 23) took part in this study. Trunk control was assessed through the BISFed trunk function scale (TFS) and a posturographic test battery consisting of two static and three dynamic tasks. The inter-rater reliability for the BISFed TFS was set at 94.44% of agreement. Moderate-to-high correlations were obtained between posturographic tasks (0.39 < r < 0.96; p < 0.05–0.01), while the BISFed TFS only correlated with two of the dynamic tasks and the overall dynamic score (−0.38 < r < −0.51; p < 0.05). The BISFed TFS was not able to discriminate between sport classes, whereas the static posturographic task did so (p = 0.004). Even though the current BISFed TFS presented good inter-rater reliability, it does not seem to have enough sensitivity to discriminate between BC1 and BC2. Although the static posturographic tasks were able to discriminate between sports classes, it seems necessary to develop new field tests assessing participants’ trunk stabilization abilities.