Brazilian Journal of Motor Behavior

Additional visual information on postural control mechanisms in Parkinson's disease: a pilot study

2023-10-21T01:34:04+00:00

BACKGROUND: Individuals with Parkinson’s disease (PD) have sensorimotor deficits that affect the mechanisms of postural control. Additional visual information effects on postural control mechanisms in PD were unknown.

AIM: To examine the effects of visual information on postural control mechanisms in individuals with PD.

METHOD: Seven individuals with PD and five healthy adults (controls) stood, as quiet as possible, on a force plate for 35 seconds with eyes open, eyes closed, or with additional visual feedback [VF] of the center of pressure (COP). The COP trajectories were calculated in anterior-posterior and mediolateral directions and then decomposed to assess two postural control mechanisms: Rambling (i.e., supraspinal) and Trembling (i.e., peripheral). The amplitude and velocity of COP and Rambling and Trembling components were compared between groups for each visual condition.

RESULTS: The amplitude and velocity of COP and its components were greater in individuals with PD than controls. They increased under closed eyes condition for PD group, but only the Rambling velocity increased in anterior-posterior direction for controls. When additional VF of the COP was provided, individuals with PD presented increased COP and Trembling velocity in mediolateral direction, while healthy individuals presented reduced sway in both directions.

CONCLUSION: Individuals with PD showed greater postural sway and were more affected without visual information than controls. They were not able to use the additional VF to reduce their postural sway as healthy individuals due to changes in sensory integration, causing possible overload in supraspinal processes and compensatory effects in the peripheral postural control mechanisms.

How the multiplanar trunk resistance affects the dynamic postural control during single-leg vertical jumps in college athletes with poor movement quality

2024-03-19T18:02:55+00:00

BACKGROUND: Poor movement quality of the trunk and the lower limbs as well as dynamic postural control have a strong relation with non-contact injuries in sport. Aiming to reduce the risk of injuries, training approaches using loaded jumps with trunk resistance have been proposed.

AIM: To describe how a multiplanar trunk load affects the dynamic postural control and the peak vertical ground reaction force of college athletes with poor movement quality of the trunk and the lower limbs.

METHOD: Center of Pressure (COP) variables and peak vertical ground reaction force of 24 female college athletes during single-leg jumps with and without a trunk resistance were compared.

RESULTS: There was a significant decrease of the COP displacement (p=0.006), RMS (p=0.009) and velocity (p=0.007) in the anteroposterior direction, and an increase of the COP displacement (p=0.016), RMS (p=0.043) and velocity (p=0.043) in the mediolateral direction, with a moderate effect size. No significant difference was found in the peak vertical ground reaction force.

CONCLUSION: Exercises involving multiplanar trunk resistance may negatively impact dynamic postural control in women with poor movement quality.

Symmetric analysis in a wheelchair basketball player during an incremental intermittent test: a case study

2023-10-28T14:04:49+00:00

BACKGROUND: Wheelchair basketball (WB) is a sport aimed at people with permanent disabilities in the lower limbs, with a functional classification system that allows the inclusion of various levels of injury from 1 to 4.5. Thus, it is natural that there is an increase in the search for greater sports performance which is related to physiological and kinematic analyses.

AIM: The present study aimed to compare the symmetry of temporal kinematic variables in the different zones of effort intensity during an incremental intermittent field test.

METHOD: The sample consisted of 1 male player aged (27 years), with spinal cord injury, with more than 5 years of gaming experience. The player performed the incremental field Yo-Yo Test - IR1 and the linear kinematics of the propulsive cycle was estimated.

RESULTS: The results indicated that wheelchair propulsion is a symmetrical movement, although some asymmetries seem to be perceived qualitatively, but without a statistically significant difference.

CONCLUSION: It was found that despite the injury to the right shoulder, there is symmetry in terms of wheelchair propulsion.

Motor proficiency in young children with Prader-Willi syndrome: a preliminary report

2023-10-21T01:27:41+00:00

BACKGROUND: Systematic documentation of motor characteristics in young children with Prader-Willi syndrome (PWS) is vital as access to treatments improves.

AIM: To characterize motor proficiency (MP) in young children with PWS.

METHOD: Participants included 6 children (3 male and 3 female) with PWS and 13 children with neurotypical development (NT), (9 male and 4 female) ages 4-6 years. Five out of six children with PWS had been on growth hormone replacement therapy (GHRT) for >3 years. Some children with PWS exhibited cognitive delays and others performed within the average range (Intellectual quotient mean± standard deviation = 65.3 ± 7.62, range = 47 – 94). MP was measured using the Short Form of the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition (BOT-2-SF).

RESULTS: Children with PWS scored lower than children with NT in all areas of MP except for fine motor integration. All children with PWS scored well-below average for total MP; children with NT scored average (n=10) or above-average (n=3) for total MP, respectively.

CONCLUSION: At this young age children with PWS universally exhibited poor MP despite most of them being on GHRT and some exhibited intellectual functioning in the average range. Evidence of BOT-2-SF floor effects underscores the need to refine assessment procedures and enhance measurement precision for this population.

Study protocol: Responsiveness of Postural Control of Children With and Without a Developmental Coordination Disorder After Transcranial Direct Current Stimulation

2023-11-30T17:21:28+00:00

BACKGROUND: Developmental coordination disorder (DCD) is a neurodevelopmental disorder that affects around 5% of school-age children worldwide. DCD negatively impacts motor repertoire, quality of life, and overall health. One of the main motor impairments affecting activity and participation is poor postural balance. Although the neural basis of DCD is not yet clear, morphological and functional alterations have been found in children with DCD in crucial areas for postural control, such as the cerebellum and the primary motor cortex. Transcranial direct current stimulation (tDCS) is a noninvasive technique for inducing synaptic modulation, promoting neuromodulation that can help in understanding physiopathology and determining therapeutic strategies for people with DCD.

AIM: The proposed randomized clinical trial will verify the immediate effects of tDCS in the primary motor cortex and the cerebellum on postural balance in children with and without DCD.

METHOD: Fifteen children with DCD and 15 typically developing children will be randomized to receive a single session of anodal cerebellar tDCS, cathodal cerebellar tDCS, anodal primary motor cortex tDCS, or sham tDCS in a crossover design. Postural balance will be assessed by posturography with and without visual and somatosensory system manipulation immediately before and after each tDCS session.

RESULTS AND INTERPRETATION: This paper presents a detailed description protocol of a double-blind, placebo-controlled, crossover clinical trial. The results can bolster understanding of the postural control of children with DCD compared to children with typical development as well as knowledge about the possible effects of tDCS on the postural balance of such children.

Knee extensor electromyographic activity during different depths of squat exercise in strength training experienced adults: A Systematic Review

2024-03-19T12:39:48+00:00

ACKGROUND: Changes in range of motion during partial and deep squats can affect the electrical activity of the knee extensor muscles. There are results’ divergences between studies that evaluated the effects of deep and partial squats on the electrical activity of the knee extensor muscles.

AIM: To systematically review the literature on the electromyographic activity of the knee extensor muscles during partial and deep squat exercises in subjects with strength training experience.

METHOD: The search included MEDLINE (via Pubmed), Scielo, EMBASE, in addition to a manual search, until June 2023. Cross-sectional observational studies comparing partial squats (up to 90º of knee flexion) and deep squats (maximum knee flexion) that evaluated the electrical activation through surface electromyography in men and women with strength training experience were included. Methodological quality assessment was performed using the adapted Downs and Black tool, as suggested by the Cochrane Collaboration.

RESULTS: Of the 636 articles identified, four studies were included. The included studies presented electromyographic values of the two squat variations. No difference was found in the activation of the rectus femoris, vastus medialis and vastus lateralis muscles between partial and deep squats. Regarding methodological quality, one study was classified as having moderate and the other three studies showing high methodological quality.

CONCLUSION: The similarity in the knee extensors’ electromyographic activation between partial and deep squat exercises in men and women with strength training experience suggests that both exercises can be used for recruiting these muscles during physical fitness activities.

Added cognitive demand from increased sensorimotor complexity resulted in better goal-directed movement following stroke: a novel finding in post-stroke recovery

2023-11-30T17:15:43+00:00

BACKGROUND: Stroke often causes impairments in goal-directed movements, which are commonly assessed using goal-directed reaching tasks. Here we present two individuals post-stroke who performed two robotic reaching tasks: 1. Visually Guided Reaching (VGR); reaching a cursor representing the fingertip to virtual targets, 2. Reverse Visually Guided Reaching (RVGR); where the cursor moves in the opposite direction of hand motion, requiring a novel cognitive rule. Participants are typically more successful at reaching targets in the simple VGR task compared to the more complex RVGR task (~92% of our database). The two cases are notable as they performed better on RVGR compared to VGR.

CASE DESCRIPTIONS: Case 1: 80-year-old patient with left hemorrhagic thalamic stroke, with interventricular extension, presenting with right hemiparesis/reduced motor control. They were unable to complete reaches to any targets in VGR (0/40 targets), but were able to reach ~30% of the targets (15/48) in RVGR. Case 2: 76-year-old patient with a left ischemic pontine stroke, presenting with right hemiparesis/reduced motor control. They were unable to complete reaches to any targets in VGR (0/40) but were able to reach ~60% of the targets in RVGR (29/48).

INTERPRETATION: Better performance in RVGR compared to VGR may be associated with a “dual-task benefit” and has potential clinical implications, including informing neuro-rehabilitative strategies, potentially by including tasks with added complexity or cognitive components. These findings also highlight the utility of robotic tools to provide novel environments within which to identify unique patterns of impairments and abilities.

Neuromusculoskeletal modeling in health and disease

2024-03-12T12:28:56+00:00

This opinion paper provides an overview of musculoskeletal modeling, revealing insights into muscle-tendon kinematics, forces, and joint contact forces during dynamic movements, thereby advancing our understanding of biomechanics. While subject-specific modeling poses challenges, emerging software tools enable rapid personalization of musculoskeletal geometry and motor control, enhancing physiological accuracy. Advanced predictive simulations and multi-scale modeling expand clinical applications, facilitating surgery outcomes prediction and movement modification for joint diseases. Collaborative interdisciplinary efforts are essential for overcoming challenges, refining workflows, and ultimately enhancing clinical treatment outcomes.