Dynamic Postural Control in Children: Do the Arms Lend the Legs a Helping Hand?

Influence of protocol variables on outcomes of the star excursion balance test group (SEBT, mSEBT, YBT-LQ) in healthy individuals: a systematic review

Background

The "SEBT group," which includes the Star Excursion Balance Test (SEBT), its modified version (mSEBT), and the Lower Quarter Y-Balance Test (YBT-LQ), is used to assess the limits of stability. Interestingly, the testing protocol allows users a considerable degree of flexibility, which can affect the obtained results. Therefore, the objective of this systematic review was to analyze the impact of different protocol variants within the "SEBT group" on outcomes.

Methods

Data were acquired by searching 4 databases (MEDLINE, ScienceDirect, Wiley, Springer Link) focusing on studies published in English in peer-reviewed journals, empirical in nature, conducted on healthy individuals, and examining the effects of various protocol variants on test outcomes. Study quality was assessed with the NHLBI quality assessment tool for pre-post studies with no control group.

Results

The calculation method based on the maximum repetition yields statistically significantly higher results compared to other calculation methods. Allowing unrestricted arm movements during the test results in statistically significantly higher scores compared to the procedure that restricts arm movements. The impact of a warm-up, wearing footwear during testing, and using a dedicated kit remains ambiguous. To obtain reliable results, 4-6 familiarization trials are necessary, though fewer may suffice for athletes experienced in performing the test.

Conclusion

This systematic review highlights the significant impact of the calculation method and arm movement restrictions on the outcomes of the "SEBT group." The effects of wearing footwear during testing, warm-up, and using a dedicated test kit remain unclear. The required number of familiarization repetitions may varies depending on biological maturity level of the person being tested. Future research should develop a warm-up protocol tailored to the needs of the "SEBT group," and investigate the impact of heel elevation during testing on outcomes.

Systematic review registration

The protocol for this systematic review was prospectively registered in the OSF Registries (https://doi.org/10.17605/OSF.IO/JSKH2).

Exploring how arm movement moderates the effect of lower limb muscle fatigue on dynamic balance in healthy youth

Background

In young adults, there is evidence that free arm movements do not help to compensate muscle fatigue-induced deteriorations in dynamic balance performance. However, the postural control system in youth is immature, and as a result, the use of arm movements may provide a compensatory "upper body strategy" to correct fatigue-related balance impairments. Thus, the purpose of the present study was to compare the effects of free vs. restricted arm movement on dynamic balance performance prior and following exercise-induced muscle fatigue.

Methods

Forty-three healthy youth (19 females; mean age: 12.8 ± 1.9 years) performed the Y Balance Test-Lower Quarter before and immediately after a fatiguing exercise (i.e., repetitive vertical bipedal box jumps until failure) using two different arm positions: free (move the arms freely) and restricted (keep the arms akimbo) arm movement.

Results

Muscle fatigue (p ≤ 0.033; 0.10 ≤ η p 2 ≤ 0.33) and restriction of arm movement (p ≤ 0.005; 0.17 ≤ η p 2 ≤ 0.46) resulted in significantly deteriorated dynamic balance performance. However, the interactions between the two did not reach the level of significance (p ≥ 0.091; 0.01 ≤ η p 2 ≤ 0.07).

Conclusion

Our findings indicate that the use of an "upper body strategy" (i.e., free arm position) has no compensatory effect on muscle fatigue-induced dynamic balance deteriorations in healthy youth.

The effects of improvement in upper extremity function on gait and balance in children with upper extremity affected

BACKGROUND

This study aimed to investigate the effects of functional improvement in the upper extremity on gait and balance in children with upper extremity affected.

RESEARCH QUESTION

What are the effects of functional improvement in the upper extremity on gait and balance in children with upper extremity affected?

METHODS

Eighteen children with a diagnosis of rheumatologic diseases and 15 healthy children were evaluated with Shriners Hospital Upper Extremity Assessment, Jebsen-Taylor Hand Function Test, Abilhand Rheumatoid Arthritis Scale, 10-meter walk test and Childhood Health Assessment Questionnaire. For static balance assessment, the Biodex Balance was used. Ground reaction forces (peak forces (heel strike and push-off) and minimum force (loading response), single-limb support duration, Center-of-Force displacement and walking speed were evaluated with the Sensor Medica. Arm swing was evaluated with the Kinovea 2D motion analysis.

RESULTS

Before treatment, single-limb support duration and push-off force was higher and center-of-force displacement was lower on affected side compared to unaffected side in rheumatologic group. After the 6-week rehabilitation program, upper extremity function, quality of life and functional gait score improved. Single-limb support duration decreased on affected side and increased on unaffected side. On affected side, push-off force decreased. The arm swing parameters were similar before and after treatment.

SIGNIFICANCE

Improving upper extremity function can help with gait balance by decreasing the difference in walking and balance parameters between the affected and unaffected sides and providing for more symmetrical weight transfer.

Effects of free versus restricted arm movements on postural control in normal and modified sensory conditions in young and older adults

The purpose of this study was to explore the effects of arm movements on postural control when standing under different sensory conditions in healthy young and older adults. Fifteen young (mean ± SD age; 21.3 ± 4.2 years) and 15 older (mean ± SD age; 73.3 ± 5.0 years) adults completed the modified Romberg test, which uses four task manipulations (i.e. eyes open and eyes closed on a firm and foam surface) to compromise the fidelity of sensory feedback mechanisms. Each participant completed the tasks under two arm movement conditions: restricted and free arm movements. Centre of pressure (COP) range and frequency were calculated to characterise postural performance and strategy, respectively. Older adults showed greater COP range with restricted compared to free arm movements during all modified sensory conditions, with these effects most prominent in the medio-lateral (ML) plane (all p < .05, Cohen's d = 0.69-1.61). Compared to the free arm movement condition, there was an increase in ML displacement and frequency when arm movements were restricted during only the most challenging (i.e. vestibular dominant) task in young adults (all p < .05, d = 0.645-0.83). Finally, main age effects for the arm restriction cost (p < .05) indicates a greater reliance on an upper body strategy in older compared to young adults, independent of sensory availability/accuracy. These findings indicate that older adults compensate for the loss of accuracy in sensory input by increasing reliance on upper body movement strategies.

Distinct clusters of movement entropy in children's exploration of a virtual reality balance beam

Although assessing motor competence is vital to advancing current understandings of motor development and its significance in various fields, no consensus exists on how the construct should be operationalised and measured. Existing approaches to assessing motor competence in children typically involve applying qualitative and/or quantitative scoring procedures in which children's performance is evaluated according to certain levels of assessment-specific task performance dependent upon predefined sets of instructions and procedures. Building upon ecological dynamics as a framework, different levels of motor competence can be identified in children's attempts to coordinate their degrees of freedom while trying to complete the interactive task and environmental constraints. Given the dynamic, nonlinear features of that coordinating process, assessments need to consider the inherit structure of inter- and intra-individual variability in patterns of movement. Against that background, we investigated 7-10-year-old children's (n = 58) whole-body joint kinematics as they freely explored a balance beam in a virtual reality playground. Specifically, we used exploratory cluster analysis to examine the discriminatory capability of utilising joint-specific sample entropy as a window into individual differences in movement coordination that emerged from children's exploration of the constraints embedded in the virtual task. Among the results, three clusters of children with distinct profiles of movement variability emerged, all of which showed heterogeneous levels of repeatability in joint movements in combination with the level of spatiotemporal exploration on the balance beam that could not be explained by between-cluster differences in age and gender distributions. Those findings suggest that entropy from whole-body movements can be used to cluster children into distinct groups with different profiles regarding the structure of movement variability, which can inform new understandings and the development of gross motor competence assessments for children.

Effects of arm movement strategies on emotional state and balance control during height-induced postural threat in young adults

BACKGROUND

It is firmly established that postural threat seems to lead to an increased. reliance on an ankle control ('stiffening') strategy. However, little is known about how. postural threat affects performance in challenging tasks that require the use of upper. body postural control strategies for stability. It is logical to assume that in such. conditions, being able to utilise an upper body strategy may reduce the reliance on. such ankle stiffening strategy. Research question The objective of this study was to determine how arm movement. influences balance control during a challenging balance task performed under. conditions of postural threat.

METHODS

Thirty young adults (mean ± SD age; 22.0 ± 4.0 years) balanced in tandem. stance whilst standing at both ground-level (no threat) and 0.8 m above ground. (threat). In both conditions, participants performed the task under two different arm.

POSITIONS

restricted arm movements and free arm movements. Postural sway. amplitude and frequency were calculated to infer postural stiffening response. Selfreported. emotional responses were quantified by assessing balance confidence, fear. of falling, perceived stability, and conscious balance processing.

RESULTS

Independent of arm movements, postural threat evoked an increase in fear of. falling and conscious balance processing, and reductions in balance confidence and. perceived stability. These threat-related changes in emotional state were further. amplified when arm movements were restricted. Whilst significant increases in sway. frequency during threat were observed in both arm conditions, reductions in sway. amplitude were only observed during the restricted arm movement condition.

SIGNIFICANCE

We propose that these responses likely reflect a fear-related cautious. strategy intended to reduce the postural destabilisation associated with individuals. being unable to use their arms to counter any destabilisation, as would normally be the. case in daily life.

Exploring how arm movement moderates the effect of task difficulty on balance performance in young and older adults

Emerging evidence highlights that arm movements exert a substantial and functionally relevant contribution on quiet standing balance control in young adults. Ageing is associated with "non-functional" compensatory postural control strategies (i.e., lower limb co-contraction), which in turn, may increase the reliance on an upper body strategy to control upright stance. Thus, the primary purpose of this study was to compare the effects of free versus restricted arm movements on balance performance in young and older adults, during tasks of different difficulty. Fifteen young (mean ± SD age; 21.3 ± 4.2 years) and fifteen older (mean ± SD age; 73.3 ± 5.0 years) adults performed bipedal, semi-tandem and tandem balance tasks under two arm position conditions: restricted arm movements and free arm movements. Centre of pressure (COP) amplitude and frequency were calculated as indices of postural performance and strategy, respectively. Especially in older adults, restriction of arm movement resulted in increased sway amplitude and frequency, which was primarily observed for the mediolateral direction. Further, increasing balance task difficulty raised the arm restriction cost (ARC; a new measure to quantify free vs. restricted arm movement differences in postural control) that was more prominent in older adults. These findings indicate the ARC provides a measure of reliance on the upper body for balance control and that arm movement is important for postural control in older adults, especially during tasks of greater difficulty.

Effect of arm movement on balance performance in children: role of expertise in gymnastics

OBJECTIVE

Studies have shown that balance performance is better in gymnasts compared to age-/sex-matched controls and further studies revealed superior performance when arms were free to move during assessment of balance. However, it is unknown whether free arm movement during balance testing differentially affects balance performance with respect to sports expertise (i.e., gymnasts are less affected than age-/sex-matched controls). Therefore, we investigated the effect of arm movement on balance performance in young female gymnasts compared to age-/sex-matched controls while performing balance tasks with various difficulty levels.

RESULTS

In both samples, balance performance (except for the timed one-legged stance) was significantly better during free compared to restricted arm movement conditions and this was especially observed in the highest task difficulty condition of the 3-m beam walking backward test. These findings revealed that balance performance is positively affected by free arm movements, but this does not seem to be additionally influenced by the achieved expertise level in young gymnasts.

Effect of arm movement and task difficulty level on balance performance in healthy children: are there sex differences?

OBJECTIVE

In children, studies have shown that balance performance is worse in boys compared to girls and further studies revealed inferior performance when arm movement was restricted during balance assessment. However, it remains unclear whether restriction of arm movement during balance testing differentially affects children's balance performance (i.e., boys more than girls). Thus, we compared the influence of arm movement on balance performance in healthy boys versus girls (mean age: ~ 11.5 years) while performing balance tasks with various difficulty level.

RESULTS

In nearly all tests, balance performance (i.e., timed one-legged stance, 3-m beam walking backward step number, Lower Quarter Y-Balance test reach distance) was significantly worse during restricted compared to free arm movement but without any differences between sexes or varying levels of task difficulty. These findings indicated that balance performance is negatively affected by restriction of arm movement, but this does not seem to be additionally influenced by children's sex and the level of task difficulty.

Effect of Arm Movement and Task Difficulty on Balance Performance in Children, Adolescents, and Young Adults

Background

Studies have shown that restricted compared to free arm movement negatively affects balance performance during balance assessment and this is reinforced when the level of task difficulty (e.g., varying stance/walk conditions, sensory manipulations) is increased. However, it remains unclear whether these findings apply to individuals with differences in the development of the postural control system. Thus, we examined the influence of arm movement and task difficulty on balance performance in children, adolescents, and young adults.

Methods

Static, dynamic, and proactive balance performance were assessed in 40 children (11.5 ± 0.6 years), 30 adolescents (14.0 ± 1.1 years), and 41 young adults (24.7 ± 3.0 years) using the same standardized balance tests [i.e., one-legged stance (OLS) time with eyes opened/closed and/or on firm/foam ground, 3-m beam (width: 6, 4.5, or 3 cm) walking backward step number, Lower Quarter Y-Balance test (YBT-LQ) reach distance] with various difficulty levels under free vs. restricted arm movement conditions.

Results

In all but one test, balance performance was significantly better during free compared to restricted arm movement. Arm by age interactions were only observed for the YBT-LQ and post hoc analyses revealed significantly greater performance differences between free and restricted arm movement, especially, in young adults. Arm by age by task difficulty interactions were found for the OLS and the 3-m beam walking backward test. Post hoc analyses showed significantly greater performance differences between free and restricted arm movement during high vs. low levels of task difficulty and this was more pronounced in children and adolescents.

Conclusions

Regardless of age, static, dynamic, and proactive balance performance benefited from arm movements and this was especially noted for youth performing difficult balance tasks.

Gross motor impairment and its relation to social skills in autism spectrum disorder: A systematic review and two meta-analyses

Gross motor ability is associated with profound differences in how children experience and interact with their social world. A rapidly growing literature on motor development in autism spectrum disorder (ASD) indicates that autistic individuals exhibit impairment in gross motor skills. However, due to substantial heterogeneity across studies, it remains unclear which gross motor skills are impaired in ASD, when and for whom these differences emerge, and whether motor and social impairments are related. The present article addressed these questions by synthesizing research on gross motor skills in ASD in two separate meta-analyses. The first examined gross motor deficits in ASD compared to neurotypical (NT) controls, aggregating data from 114 studies representing 6,423 autistic and 2,941 NT individuals. Results demonstrated a significant overall deficit in gross motor skills in ASD (Hedges' g = -1.04) that was robust to methodological and phenotypic variation and was significant at every level of the tested moderators. However, moderation analyses revealed that this deficit was most pronounced for object control skills (i.e., ball skills), clinical assessment measures, and movements of the upper extremities or the whole body. The second meta-analysis investigated whether gross motor and social skills are related in ASD, synthesizing data from 21 studies representing 654 autistic individuals. Findings revealed a modest but significant overall correlation between gross motor and social skills in ASD (r = 0.27). Collectively, results support the conclusion that motor deficits are tied to the core symptoms of ASD. Further research is needed to test the causality and directionality of this relationship. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Changes in joint kinematics and dynamic postural stability with free and restricted arm movements in children

BACKGROUND

Arm movements make a substantial and functionally relevant contribution to quiet standing and dynamic balance tasks. The impact of restricted arm movements on balance control is particularly important for children as their postural control system is not fully matured.

RESEARCH QUESTION

This study investigated the effects of arm movements on lower body joint kinematics and dynamic postural stability during anterior and lateral dynamic movements in children.

METHODS

Eighteen boys (age, 10.1 ± 1.6 years) completed an anterior and a lateral jump-landing task under two different verbally conveyed instructions of arm position; (1) arms placed flat across the chest touching the contralateral shoulder (i.e., restricted arm movement) and (2) arm movement without restriction. Lower body joint kinematics were recorded and used to calculate mean joint position, joint range of motion (ROM) and joint movement variability.

RESULTS

Restricting arm movements resulted in a reduction of joint movement variability and joint ROM of the pelvis during the lateral jump (p <0.05), but increased joint movement variability and joint ROM of the pelvis during the anterior jump (p <0.05).

SIGNIFICANCE

The reduced joint movement variability and joint ROM with restricted arm movements during the lateral jump may represent a potential compensatory 'stiffenin strategy', whilst the increase during the anterior jump suggest an exploratory strategy. These novel findings highlight that it is important for children to be introduced to different dynamic task constraints so that they can learn to control and organise the motor system degrees of freedom appropriately.

Age-Related Changes in Concentric and Eccentric Isokinetic Peak Torque of the Trunk Muscles in Healthy Older Versus Younger Men

This study investigated age-related changes in trunk muscle function in healthy men and the moderating effect of physical activity. Twelve older (67.3 ± 6.0 years) and 12 younger (24.7 ± 3.1 years) men performed isokinetic trunk flexion and extension tests across a range of angular velocities (15°/s-180°/s) and contractile modes (concentric and eccentric). For concentric trunk extension, mixed-effects analysis of covariance revealed a significant interaction between Angular velocity × Age group (p = .026) controlling for physical activity. Follow-up univariate analysis of covariance revealed that the younger group produced significantly greater peak torque for all concentric extension conditions. Eccentric trunk strength was somewhat preserved in the older group. Age-related changes in trunk strength were independent of physical activity. The normal loss of trunk muscle strength in older age is muscle- and contractile-mode specific. These findings provide guidance for effective intervention strategies to offset adverse health outcomes related to trunk strength loss in older adults.

Maturation of the postural control in adolescent girls: A 3-year follow-up study

BACKGROUND

Stable posture is a manifestation of the appropriate functioning of the neuromuscular system that is essential for proper motor development and control. Balance and stability of the erect posture are shaped during the entire childhood to culminate in its full efficiency in adolescent subjects.

METHODS

In this 3-year follow-up study, the process of the postural control maturation has been assessed in a group of 18 girls at the transition period between childhood to adolescence. Their balance and postural stability control were assessed using standard static posturography supplemented by two postural stability tests: the rising-on-toes (ROT), and the maximum forward lean (MFL), all performed with (EO) and without vision (EC). Balance control was analyzed with the sway vector (SV) and sway directional indices, whereas the anteroposterior trajectories of the center-of- pressure (COP) during forward-leaning and the raise-on-toes tests were used to determine changes in postural stability control.

RESULTS

The study documented that stability control in girls aged 11-13 is shaped according to their own pace of development. Their postural sway was characterized by the lower COP velocity but very sensitive to visual input. The directional sway measures remained at the same level for the entire period of observation. MFL and ROT tests provided similar information on postural stability and its dependence on visual input. These tests allow for more thorough assessment of postural stability to compare with quiet stance testing.

SIGNIFICANCE

Subtle changes in postural control in adolescents could be assessed based on the results of combined static and dynamic tests. In particular, the ROT test can be recommended for the assessment of postural stability.

Can arm movements improve postural stability during challenging standing balance tasks?

BACKGROUND

There is growing evidence that arm movements make a substantial and functionally relevant contribution to dynamic balance. Additional insight of the important role of arm movements may be gained by quantifying the effects of arm restriction on the performance of commonly recommended static balance tasks of increasing difficulty.

RESEARCH QUESTION

The purpose of the present study was to determine whether restricting/permitting arm movements influences postural sway during tasks of various levels of difficulty.

METHODS

A total of 20 healthy and physically active adults (females; n = 10; age, 20.7 ± 1.3 years) randomly completed (a) quiet standing postural control tasks of increasing difficulty (bipedal, tandem, unipedal) on a fixed and foam surface, and (b) a dynamic postural control task (Y balance test), under two different verbally conveyed instructions of arm position; (1) restricted arm movement and (2) free arm movement. Centre of pressure outcomes measured during quiet standing served as a measure of static balance performance.

RESULTS

The results showed that restricting movements of the arms elicited large magnitude (Cohen's d = 0.97 - 1.28) increases in mediolateral postural sway (P < 0.05) but not anteroposterior (P > 0.05) sway. These effects were only observed during challenging (tandem and unipedal) standing balance tasks. Restricting arm movements elicited a marked reduction in the Y Balance reach distance (all directions, P < 0.001, d = -0.53 to -1.15).

SIGNIFICANCE

The findings from the present study suggest that the contribution of the arms only become relevant when frontal plane balance is challenged. Moreover, the data indicate that arm movements are vital for the control of mediolateral postural sway.