Muscle Activation During Pilates Exercises in Participants With Chronic Nonspecific Low Back Pain: A Cross-Sectional Case-Control Study.

OBJECTIVE: To determine the amplitude of the electromyographic activity of trunk muscles during Pilates exercises in women with and without chronic low back pain (LBP). DESIGN: Case-control study. SETTING: University physical therapy clinic. PARTICIPANTS: Women (N=60) divided into an LBP group and a control group. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Amplitude of the electromyographic activity (root mean square values) of the gluteus maximus and external oblique muscles collected during 3 Pilates exercises: Shoulder Bridge performed on the mat, and Hip Roll and Breathing performed in equipment. Pain intensity was assessed in the LBP group. RESULTS: The amplitude of the electromyographic activity was similar between groups (P≥.05). For both groups, the amplitude of the gluteus maximus was higher in the Shoulder Bridge exercise compared with the Hip Roll with 2 springs (control group: mean difference [MD]=.18; 95% confidence interval [CI], .05-.41; LBP group: MD=.29; 95% CI, .16-.31) and the Breathing exercise (control group: MD=-.40; 95% CI, -.55 to -.26; LBP group: MD=-.36; 95% CI, -.52 to -.20). The amplitude of the external oblique muscle was higher in the Shoulder Bridge compared with the Hip Roll with 2 springs (control group: MD=.13; 95% CI, .05-.21; LBP group: MD=.18; 95% CI, .03-.33). Pain intensity increased after exercises, but this increase was lower for the mat exercises. CONCLUSIONS: Similar muscle activation between groups was found. The findings suggest that mat exercises caused less pain and a greater difference in the amplitude of muscle activation compared with the equipment-based exercises.

Assessment of the Ipsilesional Hand Function in Stroke Survivors: The Effect of Lesion Side.

BACKGROUND: The aim of this study was to examine the effect of the side of brain lesion on the ipsilesional hand function of stroke survivors. METHODS: Twenty-four chronic stroke survivors, equally allocated in 2 groups according to the side of brain lesion (right or left), and 12 sex- and age-matched healthy controls performed the Jebsen-Taylor Hand Function Test (JTHFT), the Nine-Hole Peg Test (9HPT), the maximum power grip strength (PwGSmax) test, and the maximum pinch grip strength (PnGSmax) test. Only the ipsilesional hand of the stroke survivors and both hands (left and right) of the controls were assessed. RESULTS: PwGS max and PnGS max were similar among all tested groups. Performances in JTHFT and 9HPT were affected by the brain injury. Individuals with left brain damage showed better performance in 9HPT than individuals with right brain damage, but performance in JTHFT was similar. CONCLUSIONS: Individuals after a brain injury have the capacity to produce maximum strength preserved when using their ipsilesional hand. However, the dexterity of their hands and digits is affected, in particular for stroke individuals with right brain lesion.

Relationship of diminished interjoint coordination after stroke to hand path consistency.

Differences between 12 left-brain (LCVA, 65.4 ± 11.7 years old) and 10 right-brain (RCVA, 61 ± 12.1 years old) chronic stroke survivors and 10 age-matched control adults in coordinating specific joint motions of the arm to stabilize hand path when reaching to a central target were investigated in this study. The importance of coordinating joints to stabilize hand path was tested by comparing results from uncontrolled manifold (UCM) analysis performed on experimental data versus simulated data where the covariation (coordination) between particular joint motions was removed from the original data set. UCM analysis allowed estimation of the joint configuration variance magnitude that led to hand path variability (V ORT), where the extent of increase in V ORT after removing a joint's covariation indicated how well coordinated its motion actually was with those of the other joints. The more strongly coordinated a joint was with other joints, the greater effect removal of its covariance should have on indices of hand path stability. For the paretic arm of stroke survivors, simulated removal of a joint's covariation, mainly that of shoulder with elbow and wrist, led to less change in the magnitude of V ORT compared to the same arm of control subjects. These findings confirm a reduced ability of the motion of proximal joint from paretic arm to combine flexibly with motions of the distal joints to stabilize hand path.

Aiming Movement After Stroke: Do Time-Since-Injury and Impairment Severity Influence Ipsilateral Performance?

In this cross-sectional study, we evaluated post-stroke ipsilesional (less affected) upper limb aiming movement in individuals whose strokes were either 2-5 months (n = 16) or >6 months (n = 17) prior to our testing; we also compared both stroke groups to a control group of healthy individuals (n = 14). We evaluated the participants' level of movement impairment in the contralateral upper limb from the site of the cerebrovascular lesion as an indicator of the severity of the participants' impairment. Participants were asked to move a stylus on a tablet with their ipsilesional upper limb according to a visual stimulus seen on a monitor. Those who had experienced more recent strokes showed poorer movement planning and execution, regardless of their impairment level. Since the stroke occurred, the amount of time was significantly associated with the ipsilesional aiming movement, and improvement over time brought performance levels closer to that of healthy controls.

Ipsilesional arm reaching movements are not affected by the postural configuration adopted by individuals with stroke.

Individuals with stroke present several impairments in the ipsilesional arm reaching movements that can limit the execution of daily living activities. These impairments depend on the side of the brain lesion. The present study aimed to compare the arm reaching movements performed in sitting and standing positions and to examine whether the effects of the adopted posture configuration depend on the side of the brain lesion. Twenty right-handed individuals with stroke (half with right hemiparesis and a half with left hemiparesis) and twenty healthy adults (half used the left arm) reached toward a target displayed on a monitor screen placed in one of three heights (i.e., upper, central, or lower targets). Participants performed the reaches in sitting and standing positions under conditions where the target location was either well-known in advance (certainty condition) or unknown until the movement onset (uncertainty condition). The values of movement onset time, movement time, and constant error were compared across conditions (posture configuration and uncertainty) and groups for each target height. Individuals with stroke were slower and spent more time to start to move than healthy participants, mainly when they reached the superior target in the upright position and under the uncertainty condition. Individuals who have suffered a right stroke were more affected by the task conditions and those who suffered a left stroke showed less accurate reaches. Overall, these results were observed regardless of the adopted posture. The current findings suggested that ipsilesional arm reaching movements are not affected by the postural configuration adopted by individuals with stroke. The central nervous system modulates the reaching movements according to the target position, adopted posture, and the uncertainty in the final target position to be reached.

The walking cane length influences the postural sway of community-dwelling older women.

BACKGROUND: Mobility-related problems in older people may be relieved by the use of walking canes. However, the influence of the cane length on the postural stability of cane users has not been explored. OBJECTIVE: The objective of this study is to examine the influence of a single-point cane with different lengths on the postural sway of regular cane users, older women during two stance positions, with feet parallel and semi-tandem stance. METHODS: Eighteen older women, who used a single-point walking cane for at least 6 months, stood on a force plate with feet parallel or in semitandem position for 40 s. They always used a cane that was adjusted to one of three different lengths resulting from the distance between the wrist crease and the floor, named WF, or this distance plus 7.5 or 10 cm. Amplitude and speed of the centre of pressure (COP) and its components (rambling and trembling) in the anterior-posterior and medial-lateral directions and mean vertical force applied to the cane were compared across cane lengths. RESULTS: The amplitude and velocity of COP, rambling and trembling increased with the cane length. This effect was observed for the anterior-posterior with the feet parallel and in the medial-lateral direction with the semi-tandem position. More force was applied on the shorter cane (WF) in semitandem position. CONCLUSION: Longer canes increased the postural sway in the older women and restricted the body weight loaded on the cane. Improper cane length influences the postural sway particularly in a semitandem stance of regular cane users. This may cause a negative impact on postural stability required in daily life activities. The current findings may contribute to the prescription of this assistive device for older adults.

Influence of target uncertainty on reaching movements while standing in stroke.

Stroke individuals frequently have balance problems and impaired arm movements that affect their daily activities. We investigated the influence of target uncertainty and the side of the brain lesion on the performance of arm movements and postural adjustments during reaching in a standing position by stroke individuals. Participants stood on force plates and reached a target displayed on the center of a monitor screen under conditions differentiated by the prior knowledge of the target location at the beginning of the movement. Individuals who had a stroke in the right side of the brain performed the tasks with the ipsilesional, right upper limb while the individuals with a left stroke performed with the ipsilesional, left upper limb. Healthy individuals performed with right and left limbs, which data were later averaged for statistical analysis. Kinematic analysis of the arm and lower limb joints and displacements of the center of pressure of each lower limb were compared between target conditions and groups. Stroke individuals showed larger center of pressure displacements of the contralesional compared to the ipsilesional limb while these displacements were symmetrical between lower limbs for the healthy individuals, regardless of the target condition. The target uncertainty affected both the characteristics of the arm movements and postural adjustments before movement onset. Right stroke individuals used more ankle joint movements under the uncertain compared to the certain condition. The uncertainty in target location affects the arm reaching in upright standing, but the effects depend on the side of the brain lesion.

Combined effects of the light touch and cognitive task affect the components of postural sway.

The light touch (LT) of the fingertip on a rigid surface and the performance of a cognitive task (CT) affect the postural control. The current study examined the mechanisms involved in the control of postural sway (i.e., Rambling and Trembling components of the center of pressure) with the LT and CT performed individually or simultaneously. Thirteen adults stood on a force plate for 70 s while performed the LT, CT (visual searching of specific letters) or both tasks simultaneously. COP, Rambling, and Trembling mean amplitude and speed were computed. COP and Rambling trajectories were highly and Trembling moderately reduced with LT. The CT affected mainly the Rambling component, supporting the role of supraspinal control of postural sway. These findings suggested that while LT influences both supraspinal and peripheral control mechanisms, CT influences mostly the supraspinal mechanisms involved in postural sway. The combined effects of LT and CT improve the postural control with no negative consequences on CT performance.

The effect of dyskinesia on postural control, balance, gait, and fall risk in people with Parkinson's disease: a systematic review protocol

Dyskinesia affects the limbs, trunk, and head and is more prevalent in people with Parkinson's disease (PD) and a history of falls. More evidence about the effects of dyskinesia on postural control, balance, gait, and fall risk could help improve the quality of life of individuals with PD. This review aims to examine associations between dyskinesia and postural control, balance, gait, and fall risk in individuals with PD. Such information could lead to new approaches to quality of life improvement among individuals with PD. PubMed, CINAHL, PsycInfo, Scopus, and SciELO will be searched for longitudinal, cohort, and case-control studies published in English or Portuguese in any year that investigated the association between dyskinesia and postural control, balance, gait, and fall risk in individuals with PD. Two reviewers will independently evaluate the titles, abstracts, and full texts according to PRISMA guidelines to select eligible studies for the review. Data on participants, dyskinesia, postural control, balance, gait, and fall risk will be extracted and summarized in tables. Two reviewers will independently assess the methodological quality of each study using the Newcastle Ottawa quality assessment scale. Meta-analysis will not be performed. The results of this systematic review will offer insight into the effects of dyskinesia on postural control, balance, gait, and fall risk. Such information could significantly contribute to informed decisions about early motor intervention in individuals with PD. (AU)

Individuals' perception about upper limb influence on participation after stroke: an observational study.

Background Stroke can compromise upper limb performance and influence the individual's participation in real life situations. Objective To investigate how components of body function and activity affect the individuals' self-perception of their participation after stroke. Methods In this observational study, the International Classification of Functioning, Disability and Health was used as model. Body function was assessed by palmar grip and pinch strength; Ashworth modified scale; Fugl-Meyer scale; and Motor-Free Visual Perception Test. The Purdue Pegboard Test and the aiming movement performance measured the activity. Upper limb participation was analyzed by the Hand Function domain of the Stroke Impact Scale (SIS). Thirty-four individuals after chronic stroke were divided into two groups, according to their Hand function SIS scores (severe and non-severe). Differences between groups were analyzed. Relationships between individual variables and the SIS score were verified. A regression model was proposed. Results Strength and the Fugl-Meyer scale score were greater for the non-severe group. Muscle tone was greater for the severe group only in the wrist flexors. None of the activity variables differed between groups. The upper limb Fugl-Meyer score was able to predict 79% of the individuals in SIS Hand Function groups. Conclusion Sensory-motor impairment, as measured by the upper limb Fugl-Meyer scale, can explain the influence of the upper limbs on participation in the individuals' perception.

Ipsilesional Arm Aiming Movements After Stroke: Influence of the Degree of Contralesional Impairment.

The authors examined the effects of the degree of impairment of the contralesional upper limb and the side of the hemispheric damage on ipsilesional upper limb performance in chronic stroke individuals. Right- and left-side stroke resulting in mild-to-severe impairment and healthy participants took part in simple and choice reaction time tasks involving aiming movements. The stroke individuals performed the aiming movements with the ipsilesional upper limb using a digitizing tablet to ipsi- or contralateral targets presented in a monitor. The global performance of the group with severe right hemispheric damage was worse than that of the other groups, indicating that the side of hemispheric damage and degree of motor impairment can adversely affect aiming movement performance.

The influence of a real job on upper limb performance in motor skill tests: which abilities are transferred?

To investigate whether the specificities of real jobs create distinctions in the performance of workers in different motor tests for the upper limbs, 24 participants were divided into two groups according to their specific job: fine and repetitive tasks and general tasks. Both groups reproduced tasks related to aiming movements, handling and strength of the upper limbs. There were no significant differences between groups in the dexterity and performance of aiming movements. However, the general tasks group had higher grip strength than the repetitive tasks group, demonstrating differences according to job specificity. The results suggest that a particular motor skill in a specific job cannot improve performance in other tasks with the same motor requirements. The transfer of the fine and gross motor skills from previous experience in a job-specific task is the basis for allocating training and guidance to workers.

Target height affects the symmetry of the postural adjustments after (but not prior) the onset of reaching movements in upright standing.

The present study aimed to investigate the influence of target height on the symmetry and amplitude of the postural adjustments assessed by the displacements of the center of pressure (COP) before and during the unilateral, arm movements in the upright position. Thirteen young, right-handed adults stood with each foot on one force platform and reached a target placed at one of three heights displayed on a monitor screen. The performance of the right arm movements (movement time and radial error), amplitude of the COP displacements of each lower limb and the percentage of body weight loading on the right lower limb before and during the reaching movements were compared across target heights conditions. Postural adjustments were symmetrical prior but asymmetrical after movement onset. Effect of target height was observed on the postural adjustments before and during the movements (i.e., amplitudes of the COP displacements increased for the higher target), mainly for the right limb. The arm performance was similar across target heights. The findings of the present study suggested that postural adjustments are dependent on the target heights to ensure success in the arm movements.

Effect of force magnitude of touch on the components of postural sway.

BACKGROUND: Lightly touching the tip of the index finger on an external surface reduces the postural sway during upright standing due to the additional somatosensory information provided by the touch to the postural control system. But when the individuals apply more force, it provides more mechanical support. However, because most of the studies investigated only two levels of force, whether the control mechanisms of postural sway are affected by the different force levels was unknown. RESEARCH QUESTION: To examine the influence of the magnitude of force (up to 1, 2, 4, 6 or 8 N) applied to the touch bar on the mechanisms used to control the postural sway during quiet standing with eyes open or closed. METHODS: Ten young right-handed adults stood for 35 s on a force platform, with feet apart, while touched a rigid bar with different force levels with eyes open or closed. The amplitude and velocity of the center of pressure and its components, Rambling and Trembling trajectories, respectively, related to more supraspinal and spinal control mechanisms, were assessed. RESULTS: The touch reduced all trajectories, mainly of the Rambling component and with closed eyes. There was a floor effect of the touch force as amplitudes and velocities were minimal at 4 N of force. SIGNIFICANCE: The component of postural sway under the supraspinal neural control is more affected by different force magnitudes applied to the touch bar.

Electromyographic activity of the erector spinae: The short-effect of one workday for welders with nonspecific chronic low back pain, an observational study.

OBJECTIVE: This study aimed to evaluate the effect of one workday on pain and perceived exertion, muscular strength, and electromyographic activity of the erector spinae muscles in welders with and without low back pain. This is an observational cohort study. PARTICIPANTS: Twenty-two welders, metallurgical shipbuilding, were equally divided into 2 groups: low back pain and no low back pain. Pain and perceived exertion. Muscular strength by maximal voluntary contractions and electromyographic activity of right and left erector spinae muscles during maximal voluntary contractions and in the 3 welding positions for 2 periods of the workday (in the morning and at the end of the workday). RESULTS: At the end of workday, the pain increased significantly for the low back pain group (t(22) = 2.448; P= 0.023). The perceived exertion also increased significantly for both groups at the end of workday groups (F(1,22) = 8.570, P= 0.000) and periods (F(1,22) = 8.142, P= 0.000). There were no significant differences between groups and workday periods for muscular strength and electromyographic activity during maximal voluntary contractions of the erector spinae. There was no significance difference for electromyographic activity between groups and workday period and in the 3 welding positions. CONCLUSION: Although the pain and perceived exertion increased at the end of the workday, these results did not interfere in muscular strength and electromyographic activity of right and left erector spinae muscles. Thus, we can conclude that welders with chronic low back pain had a good physical capacity (muscular strength) and that muscle performance was maintained.

Effect of motor planning on use of motor abundance.

This study examined the hypothesis that the degree to which motor redundancy is used to coordinate joint motions for reaching is influenced by motor planning and enhanced when the task requires greater movement flexibility. Subjects reached at arm's length to the same centrally placed target under conditions where the target location was either certain or uncertain, using a double-step paradigm. The hypothesis was evaluated by partitioning the across-trials variance of the joint configuration at each percent of the reach into a component corresponding to the use of different joint angle combinations to achieve an equivalent hand position (GEV) and a component leading to a variable hand position (NGEV). Pointer-tip movement variability along the path and variable targeting error did not differ between conditions. Larger overall joint variance was found for the uncertain target condition. Most of this increase was GEV, which was significantly higher in the uncertain condition for control of both movement extent and movement direction. In contrast, NGEV differed between the two conditions only for the control of movement extent early in the reach, suggesting that target uncertainty led to inter-trial timing variability along the movement path. The results suggest that more flexible patterns of joint coordination are used when the nervous system must plan reaching movements to an uncertain target direction.

Comparison of Two Methods for Estimating Adjustable One-Point Cane Length in Community-Dwelling Older Adults.

BACKGROUND AND PURPOSE: Our aim is to estimate inter-observer reliability, test-retest reliability, anthropometric and biomechanical adequacy and minimal detectable change when measuring the length of single-point adjustable canes in community-dwelling older adults. METHODS: There are 112 participants in the study. They are men and women, aged 60 years and over, who were attending an outpatient community health centre. An exploratory study design was used. Participants underwent two assessments within the same day by two independent observers and by the same observer at an interval of 15-45 days. Two measures were used to establish the length of a single-point adjustable cane: the distance from the distal wrist crease to the floor (WF) and the distance from the top of the greater trochanter of the femur to the floor (TF). Each individual was fitted according to these two measures, and elbow flexion angle was measured. RESULTS AND DISCUSSION: Inter-observer reliability and the test-retest reliability were high in both TF (ICC3.1 = 0.918 and ICC2.1 = 0.935) and WF measures (ICC3.1 = 0.967 and ICC2.1 = 0.960). Only 1% of the individuals kept an elbow flexion angle within the standard recommendation of 30° ± 10° when the cane length was determined by the TF measure, and 30% of the participants when the cane was determined by the WF measure. The minimal detectable cane length change was 2.2 cm. CONCLUSION: Our results suggest that, even though both measures are reliable, cane length determined by WF distance is more appropriate to keep the elbow flexion angle within the standard recommendation. The minimal detectable change corresponds to approximately a hole in the cane adjustment. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of direction and index of difficulty on aiming movements after stroke.

BACKGROUND: Brain hemispheres play different roles in the control of aiming movements that are impaired after unilateral stroke. It is not clear whether those roles are influenced by the direction and the difficulty of the task. OBJECTIVE: To evaluate the influence of direction and index of difficulty (ID) of the task on performance of ipsilesional aiming movements after unilateral stroke. METHODS: Ten individuals with right hemisphere stroke, ten with left hemisphere stroke, and ten age- and gender-matched controls performed the aiming movements on a digitizing tablet as fast as possible. Stroke individuals used their ipsilesional arm. The direction (ipsilateral or contralateral), size (0.8 or 1.6 cm), and distance (9 or 18 cm) of the targets, presented on a monitor, were manipulated and determined to be of different ID (3.5, 4.5, and 5.5). Results. Individuals with right hemisphere lesion were more sensitive to ID of the task, affecting planning and final position accuracy. Left hemisphere lesion generated slower and less smooth movements and was more influenced by target distance. Contralateral movements and higher ID increased planning demands and hindered movement execution. CONCLUSION: Right and left hemisphere damages are differentially influenced by task constraints which suggest their complementary roles in the control of aiming movements.

Ipsilesional arm motor sequence performance after right and left hemisphere damage.

Aiming movements are part of daily activities but the brain hemispheres' role in targeted aiming sequential movements is not fully clear. Start and execution of discrete and sequential tasks toward targets were analyzed in 10 individuals with left-hemisphere damage, 10 right-hemisphere-damaged, and 10 healthy ones. Arm movements were performed over a digitizing tablet, following stimuli on a monitor, from initial position toward right and left-positioned targets. Poststroke individuals used their ipsilesional arm and healthy individuals, both arms. Right-hemisphere-damaged individuals showed higher reaction time and left-hemisphere-damaged individuals, lower smoothness. Due to spatial demand of tasks, the right hemisphere played a major role in movement planning, while the left, in movement execution.