Center Of Pressure Path Length Research Articles

Inertial Sensor-Based Variables Are Indicators of Frailty and Adverse Post-Operative Outcomes in Cardiovascular Disease Patients.

Cardiovascular disease (CVD) patients with intrinsic cardiac cause for falling have been found to be frail and submissive to morbidity and mortality as post-operative outcomes. In these older CVD patients, gait speed is conjectured by the Society of Thoracic Surgeons (STS) as an independent predictor of post-operative morbidity and mortality. However, this guideline by STS has not been studied adequately with a large sample size; rather it is based largely on expert opinions of cardiac surgeons and researchers. Although one’s gait speed is not completely associated with one’s risk of falls, gait speed is a quick robust measure to classify frail/non-frail CVD patients and undoubtedly frail individuals are more prone to falls. Thus, this study examines the effects of inertial sensor-based quick movement variability characteristics in identifying CVD patients likely to have an adverse post-operative outcome. This study establishes a relationship with gait and postural predictor variables with patient’s post-operative adverse outcomes. Accordingly, inertial sensors embedded inside smartphones are indispensable for the assessment of elderly patients in clinical environments and may be necessary for quick objective assessment. Sixteen elderly CVD patients (Age 76.1 ± 3.6 years) who were scheduled for cardiac surgery the next day were recruited for this study. Based on STS recommendation guidelines, eight of the CVD patients were classified as frail (prone to adverse outcomes with gait speed ≤ 0.833 m/s) and the other eight patients as non-frail (gait speed > 0.833 m/s). Smartphone-derived walking velocity was found to be significantly lower in frail patients than that in non-frail patients (p < 0.01). Mean Center of Pressure (COP) radius (p < 0.01), COP Area (p < 0.01), COP path length (p < 0.05) and mean COP velocity (p < 0.05) were found to be significantly higher in frail patients than that in the non-frail patient group. Nonlinear variability measures such as sample entropy were significantly lower in frail participants in anterior-posterior (p < 0.01) and resultant sway direction (p < 0.01) than in the non-frail group. This study identified numerous postural and movement variability parameters that offer insights into predictive inertial sensor-based variables and post-operative adverse outcomes among CVD patients. In future, smartphone-based clinical measurement systems could serve as a clinical decision support system for assessing patients quickly in the perioperative period.

An Exploratory Study on the Acute Effects of Proprioceptive Exercise and/or Neuromuscular Taping on Balance Performance

Background: This study aimed at investigating the acute effects of combined EXERCISE and TAPING in comparison to isolated proprioceptive exercise (EXERCISE) and ankle neuromuscular taping (TAPING) on one - leg stability performance in rugby players. Methods: Stability tests, performed on a stabilometric platform, were assessed for stability before and after above interventions. Performed stability tests were one - leg static stance (dominant leg and non - dominant leg) each with eyes open and eyes closed. The assessed dependent variables were: centre of pressure (CoP) path length; CoP speed; medio - lateral, and anterior - posterior sway. Sixteen male rugby players (27.3 ± 3.3 years; 177.3 ± 7.3 cm; 88.8 ± 15.2 kg) from a non - professional rugby team were tested in all above conditions, according to a cross - over study design. Results: Most of investigated variables improved following EXERCISE + TAPING (CoP path length -18.2/ -15.6%, CoP speed -22.8/-17.7%, and anterior-posterior sway -21.0/ -16.3%), in comparison with the other two protocols. EXERCISE + TAPING improved the stability control by combining the effects of both proprioceptive exercise and neuromuscular taping. Conclusions: Such findings could suggest the benefits of planning long - term strategies using EXERCISE + TAPING protocols for improving the functional stability and for preventing re - occuring injuries.

Vibrotactile Feedback Alters Dynamics Of Static Postural Control In Persons With Parkinson’s Disease But Not Older Adults At High Fall Risk

BackgroundAging and Parkinson’s disease are often associated with impaired postural control. Providing extrinsic feedback via vibrotactile sensation could supplement intrinsic feedback to maintain postural control. Research questionWe investigated the postural control response to vibrotactile feedback provided at the trunk during challenging stance conditions in older adults at high fall risk and individuals with Parkinson’s disease compared to healthy older adults. MethodsNine older adults at high fall risk, 9 persons with Parkinson’s disease and 10 healthy older adults performed 30s quiet standing on a force platform under five challenging stance conditions with eyes open/closed and standing on firm/foam surface with feet together, each with and without vibrotactile feedback. During vibrotactile feedback trials, feedback was provided when participants swayed >10% over the center of their base of support. Participants were instructed vibrations would be in response to their movement. Magnitude of postural sway was estimated using center of pressure path length, velocity, and sway area. Dynamics of individuals’ postural control was evaluated using detrended fluctuation analysis. ResultsResults showed that vibrotactile feedback induced a change in postural control dynamics among persons with Parkinson’s disease when standing with intact intrinsic visual input and altered intrinsic somatosensory input, but there was no change in sway magnitude. However, use of vibrotactile feedback did not significantly alter dynamics of postural control in older adults with high risk of falling or reduce the magnitude of sway. SignificanceConsidering the effects of vibrotactile feedback were dependent on the population and stance condition, designing an optimal therapeutic regimen for balance training should be carefully considered and be specific to a target population. Furthermore, our results suggest that explicit instructions on how to respond to the vibrotactile feedback could affect training outcome.

Reliability and feasibility of gait initiation centre-of-pressure excursions using a Wii\xae Balance Board in older adults at risk of falling

BackgroundImpairments in dynamic balance have a detrimental effect in older adults at risk of falls (OARF). Gait initiation (GI) is a challenging transitional movement. Centre of pressure (COP) excursions using force plates have been used to measure GI performance. The Nintendo Wii Balance Board (WBB) offers an alternative to a standard force plate for the measurement of CoP excursion.AimsTo determine the reliability of COP excursions using the WBB, and its feasibility within a 4-week strength and balance intervention (SBI) treating OARF.MethodsTen OARF subjects attending SBI and ten young healthy adults, each performed three GI trials after 10 s of quiet stance from a standardised foot position (shoulder width) before walking forward 3 m to pick up an object. Averaged COP mediolateral (ML) and anteroposterior (AP) excursions (distance) and path-length time (GI-onset to first toe-off) were analysed.ResultsWBB ML (0.866) and AP COP excursion (0.895) reliability (ICC3,1) was excellent, and COP path-length reliability was fair (0.517). Compared to OARF, healthy subjects presented with larger COP excursion in both directions and shorter COP path length. OARF subjects meaningfully improved their timed-up-and-go and ML COP excursion between weeks 1–4, while AP COP excursions, path length, and confidence-in-balance remained stable.DiscussionCOP path length and excursion directions probably measure different GI postural control attributes. Limitations in WBB accuracy and precision in transition tasks needs to be established before it can be used clinically to measure postural aspects of GI viably.ConclusionsThe WBB could provide valuable clinical evaluation of balance function in OARF.

Reliability analysis of a sensitive and independent stabilometry parameter set.

Recent studies have suggested reduced independent and sensitive parameter sets for stabilometry measurements based on correlation and variance analyses. However, the reliability of these recommended parameter sets has not been studied in the literature or not in every stance type used in stabilometry assessments, for example, single leg stances. The goal of this study is to evaluate the test-retest reliability of different time-based and frequency-based parameters that are calculated from the center of pressure (CoP) during bipedal and single leg stance for 30- and 60-second measurement intervals. Thirty healthy subjects performed repeated standing trials in a bipedal stance with eyes open and eyes closed conditions and in a single leg stance with eyes open for 60 seconds. A force distribution measuring plate was used to record the CoP. The reliability of the CoP parameters was characterized by using the intraclass correlation coefficient (ICC), standard error of measurement (SEM), minimal detectable change (MDC), coefficient of variation (CV) and CV compliance rate (CVCR). Based on the ICC, SEM and MDC results, many parameters yielded fair to good reliability values, while the CoP path length yielded the highest reliability (smallest ICC > 0.67 (0.54–0.79), largest SEM% = 19.2%). Usually, frequency type parameters and extreme value parameters yielded poor reliability values. There were differences in the reliability of the maximum CoP velocity (better with 30 seconds) and mean power frequency (better with 60 seconds) parameters between the different sampling intervals.

Altered postural sway during quiet standing in women with clinical lumbar instability.

[Purpose] The current study aimed to investigate the center of pressure, as an indicator of postural sway, to determine any differences between women with clinical lumbar instability and asymptomatic low back pain. [Participants and Methods] Thirty healthy and fifteen clinical lumbar instability participants were measured for their postural sway in the anterior-posterior and medial-lateral directions. The women were tested for postural sway on a force plate in quiet standing and eyes closed. Center of pressure path length and mean velocity in the anterior-posterior and medial-lateral directions and total area of excursion were measured and analyzed for 30 seconds. [Results] Clinical lumbar instability participants showed a significantly increase when compared with healthy participants, in path length and mean velocity in both directions and total area of excursion. [Conclusion] The findings suggest that chronic low back pain patients with clinical lumbar instability have increased postural sway when vision is deprived. The clinical significance of this has not yet been determined but may provide an opportunity for therapy directed at improving balance control in this patient group.

Walking and balance ability gain from two types of gait intervention in adult patients with chronic hemiplegic stroke: A pilot study

ABSTRACTThis study examined whether the walking and balance ability of adult patients with chronic hemiplegic stroke are associated differentially with the degree of gain after two types of gait intervention. Twenty-four subjects with hemiplegic stroke were enrolled in this randomized study. Each subject participated in one of two gait intervention strategies: gait training with auditory feedback caused by active weight bearing on the paralyzed side (experimental group; EG), or general gait intervention over the ground (control group; CG). The walking and balance abilities were assessed before and after gait intervention. Significant improvements in the 10-m walking test, functional gait assessment (FGA) score, and center of pressure (COP) path length were observed after gait training in both groups (p < 0.05). The EG showed a larger increase in the 10-m walking test, FGA score, and COP path length in the state of eyes opened and closed than the CG (18.2%, 27.0%, 24.8%, and 18.2%, respectively). The auditory feedback caused by active weight bearing on the paralyzed side appeared to be a more effective approach for improving the walking and balance ability in adult patients with hemiplegic stroke during walking training than general gait intervention.

Biomechanical Analysis of Dance for Parkinson’s Disease: A Paradoxical Case Study of Balance and Gait Effects?

This study aimed to measure the effects of a dance training program on subjective and objective balance and gait measures in a person with Parkinson's disease. The participant was measured via clinical scales and biomechanical balance and gait analyses pre- and post-16 weeks of dance participation at the University Center for Arts in Medicine. The dance program consisted of 75 minute sessions three days a week. Improved clinical scales included the Schwab and England scale (+10%), falls efficacy scale (-11 points), six-minute walk (+15.54m), and timed up and go (1.38s). Balance measures during three conditions (eyes open, eyes closed, and narrow stance) all demonstrated an increase (24-112%) in center of pressure path length, velocity (anteroposterior and mediolateral), sway area, and approximate entropy (anteroposterior and mediolateral). Spatiotemporal gait parameters improved during forward walking: velocity (+0.12m/s), cadence (+3.89steps/min), double support time (-2.02%), stride length (+0.07m), stride time (-0.03s), and backward walking: single support (+3.47%), double support (-7.0%), swing time (+3.4%), and stance time (-3.4%). Classic interpretation of the above measures may indicate a detriment in biomechanical balance effects concomitant with an improvement in gait. Alternative explanations explored suggest this paradox to be illusory.

Men with unilateral Achilles tendinopathy have impaired balance on the symptomatic side

ObjectivesTo investigate single leg standing balance in males with mid-portion Achilles tendinopathy (AT). DesignCross sectional case study. MethodsCentre of pressure (COP) path length was measured using a Wii Balance Board (WBB) in 21 male participants (20–60 years) with unilateral mid-portion AT during single-limb standing on each limb with eyes open and closed. Ultrasound imaging of both Achilles tendons was also performed by one blinded assessor, and the anteroposterior (AP) thickness and presence of pathology was determined. Comparisons were made between symptomatic and asymptomatic sides for key outcomes, and correlation between COP path length and variables of interest were investigated. ResultsSymptomatic Achilles tendons demonstrated significantly increased AP tendon thickness (p<0.001). Participants with AT demonstrated increased COP path length (sway amplitude) on their affected side during the eyes closed task (p=0.001). Increased tendon thickness was associated with increased sway amplitude during the eyes open task on both the affected (rho=0.44, p=0.045) and unaffected sides (rho=0.62, p=0.003). ConclusionsIn males with AT, single-leg standing balance with eyes closed is impaired on the symptomatic side. This indicates that neuromuscular deficits affecting functional ability may be present in people with AT during more challenging balance activities. It is unclear if this deficit precedes the onset of symptoms, or is a consequence of tendon pain. Work is now needed to understand the mechanisms that may explain standing balance deficits among people with AT.

Virtual reality body motion induced navigational controllers and their effects on simulator sickness and pathfinding.

Virtual reality (VR) navigation is usually constrained by plausible simulator sickness (SS) and intuitive user interaction. The paper reports on the use of four different degrees of body motion induced navigational VR controllers, a TiltChair, omni-directional treadmill, a manual wheelchair joystick (VRNChair), and a joystick in relation to a participant's SS occurrence and a controller's intuitive utilization. Twenty young adult participants utilized all controllers to navigate through the same VR task environment in separate sessions. Throughout the sessions, SS occurrence was measured from a severity score by a standard SS questionnaire and from body sway by a center of pressure path length with eyes opened and closed. SS occurrence did not significantly differ among the controllers. However, time spent in VR significantly contributed to SS occurrence; hence, a few breaks to minimize SS should be interjected throughout a VR task. For all task trials, we recorded the participant's travel trajectories to investigate each controller's intuitive utilization from a computed traversed distance. Shorter traversed distances indicated that participants intuitively utilized the TiltChair with a slower speed; while longer traversed distances indicated participants struggled to utilize the omni-directional treadmill with a unnaturalistic stimulation of gait. Therefore, VR navigation should use technologies best suited for the intended age group that minimizes SS, and produces intuitive interactions for the participants.

Comparison of Path Length and Ranges of Movement of the Center of Pressure and Reaction Time and Between Paired-Play and Solo-Play of a Virtual Reality Game.

To test whether paired-play will induce longer path length and ranges of movement of the center of pressure (COP), which reflects on balance performance and stability, compared to solo-play and to test the difference in the path length and ranges of movement of the COP while playing the virtual reality (VR) game with the dominant hand compared to playing it with the nondominant hand. In this cross-sectional study 20 children (age 6.1 ± 0.7 years old) played an arm movement controlled VR game alone and with a peer while each of them stood on a pressure measuring pad to track the path length and ranges of movement of the COP. The total COP path was significantly higher during the paired-play (median 295.8 cm) compared to the COP path during the solo-play (median 189.2 cm). No significant differences were found in the reaction time and the mediolateral and anterior-posterior COP ranges between solo-play and paired-play. No significant differences were found between the parameters extracted during paired-play with the dominant or nondominant hand. Our findings imply that the paired-play is advantageous compared to solo-play since it induces a greater movement for the child, during which, higher COP velocities are reached that may contribute to improving the balance control of the child. Apart from the positive social benefits of paired-play, this positive effect on the COP path length is a noteworthy added value in the clinical setting when treating children with balance disorder.

Impairments of balance, stepping reactions and gait in people with cervical dystonia

BackgroundImpaired balance is common in neurological disorders. Cervical dystonia is a neurological movement disorder affecting the neck. The effect of this aberrant head posture on physical function is unknown. ObjectivesTo compare balance, mobility, gait and stepping reactions between ten people with cervical dystonia and ten control adults. MethodsSpatiotemporal gait parameters and walking speed were assessed using a computerised walkway. Step length and time, time in double support and gait variability were calculated, then normalised to gait speed. Centre of pressure path length was assessed with eyes open and eyes closed to calculate a Romberg Quotient. Simple and choice reaction times were measured using customised apparatus while mobility was assessed by the timed up and go. Cervical spine range of motion was measured using a head mounted goniometer. Self-reported scales included Falls Self Efficacy Scale and Dystonia Discomfort Scale. ResultsThere was a difference between groups for most outcome measures. The timed up-and-go and walking speed was slower (both P < 0.005) and the Romberg Quotient lower (P = 0.046) in cervical dystonia. People with cervical dystonia had lower falls self-efficacy (P = 0.0002). Reduced cervical range of motion was correlated with balance, stepping reaction time and mobility (all P < 0.05). Timed up and go was positively associated with stepping reaction time (P < 0.01). Dystonia discomfort did not impact function. ConclusionsPeople with cervical dystonia displayed deficits in balance, gait and stepping reactions, and expressed higher fear of falling. Studies to further elucidate functional limitations and their impact on activity and participation in daily life are required.

Postactivation depression of soleus H-reflex increase with recovery of lower extremities motor functions in patients with subacute stroke.

[Purpose] The soleus H-reflex is depressed at stimulation rates greater than 0.1 Hz. This reflex depression is referred to as postactivation depression. Postactivation depression reflects the reduced efficacy of the Ia-motoneurons synapses when they are evaluated after a previous activation. The aim of this study was to determine whether the recovery of motor functions in the lower extremities affects the PAD of the soleus H-reflex in patients with subacute stroke undergoing rehabilitation. [Subjects and Methods] Eight patients with subacute stroke patients were recruited. Postactivation depression, Fugl-Meyer score (lower-limb portion), walking velocity, the Modified Ashworth Scale, and center of pressure sway during standing were measured within three days of admission to rehabilitation and 50 days later. [Results] After rehabilitation, Fugl-Meyer scores, center of pressure path length, and walking velocity were significantly improved, and postactivation depression had significantly increased. There was a significant positive correlation between the rates of change of postactivation depression and center of pressure path length. [Conclusion] The results demonstrated that postactivation depression is partially normalized after rehabilitation in patients with subacute stroke, and suggested that the recovery in lower extremity function after stroke particularly standing stability is affected by spinal synaptic plasticity.

Reliability and validity of the protokinetics movement analysis software in measuring center of pressure during walking

Our purpose was to determine the validity and test-retest reliability of the Protokinetics Movement Analysis Software (PKMAS) in measuring center of pressure (COP) during walking as compared to a force plate gold standard. Twenty-five healthy participants (14 females, 11 males; age 20.0±1.5years) completed 2 testing sessions approximately 5days apart (mean=5.5±1.1 days). In each session, participants completed 16 total trials across a 6m walkway: 8 trials walking on a ProtoKinetics Zeno Walkway using PKMAS and 8 trials walking over 2 force plates arranged in an offset tandem pattern. COP path length (cm) and speed (cm/s) were calculated from data averaged across the 8 trials on a given device for a given foot. Intraclass correlation coefficients (ICC 2, k) were computed to determine between session reliability. Pearson correlation coefficients (r) and Bland-Altman plots were produced between the PKMAS and force plate outcomes for session 1 to determine validity. The PKMAS demonstrated excellent reliability (ICC 2, k≥0.962) for all COP measures. Pearson correlation coefficients between PKMAS and force plates were ≥0.75 for all outcome variables. Bland-Altman plots and 95% levels of agreement revealed a bias where the PKMAS appeared to underestimate COP path length and speed by approximately 4cm and 6cm/s, respectively. After correcting for bias, our findings suggest the PKMAS is a reliable tool to measure COP in healthy people during gait. Using the PKMAS with the ProtoKinetics Zeno Walkway may allow for more efficient investigation of dynamic balance variables during functional movement tasks.

Standing balance and inter-limb balance asymmetry at one year post primary anterior cruciate ligament reconstruction: Sex differences in a cohort study of 414 patients

BackgroundStatic standing balance can be safely assessed early following anterior cruciate ligament reconstruction (ACLR), and deficits may have important implications for long-term outcomes. This study includes a large cohort of people post-ACLR and has the primary aim of establishing whether inter-limb and sex differences exist, with a secondary aim of assessing the association between static balance variables and other outcome measures. MethodsA total of 414 patients with a primary ACLR performed a 30-s static single leg balance test. Centre of pressure (COP) path length, antero-posterior (AP) and medio-lateral (ML) sway range and slow and fast speed COP path-length were examined. Additional measures included single and triple hop distance and symmetry, knee flexion range of motion, ligament laxity and the International Knee Documentation Committee (IKDC) subjective knee evaluation form. ResultsNo significant inter-limb balance differences were present in females. Significant, yet small to negligible effect size (ES) differences were present in males for ML range (ES=0.19), and AP and ML axis slow speed path length (ES=0.11 and 0.23 respectively). Significant, negligible to moderate effect size (ES range=<0.01 to 0.60) sex differences were observed, with females showing reduced sway compared to males. No balance variables had associations with any other variable that were greater than weak. DiscussionOur findings provide evidence that primary ACLR does not appear to negatively impact single leg standing balance on the operated limb more than the non-operated side. The lack of association with other outcome measures warrants further longitudinal examination into the utility of static standing balance assessment.

Evaluation of psychological effects on human postural stability

Abstract Human postural stability is commonly assessed by a set of posturographic tests during quiet upright standing. Numerous studies extend these tests with cognitive and mental tasks where various physiological and biomechanical sensors are used in combination with a force plate. The aim of our study was to determine whether psychological effects of sensor attachment and the awareness of the subject being measured could influence the posturographic tests performed using the force plate. An experiment was performed where complete data from 51 participants (13 women and 38 men) were obtained in four different conditions. Posturographic tests were performed either with eyes open or eyes closed, and either with biomedical instrumentation sensors attached or not attached. The results indicate that the presence of biomedical instrumentation sensors had a statistically significant impact on the centre of pressure path length and ellipse area as well as on the perceived difficulty of the task and its pleasantness. We conclude that the attachment of sensors on the body of the participants during biomechanical experiments significantly affects the perception of the experimental situation and alters the output of posturographic tests. It is therefore important to appropriately take into account the possible effects of psychological strain (such as the awareness of being measured) in the experimental design and in the interpretation of the results.

Standing Balance and Spatiotemporal Aspects of Gait Are Impaired Upon Nocturnal Awakening in Healthy Late Middle-Aged and Older Adults.

Nocturnal awakenings may constitute a unique risk for falls among older adults. We describe differences in gait and balance between presleep and midsleep testing, and whether changes in the lighting environment during the midsleep testing further affect gait and balance. Twenty-one healthy, late middle-aged and older (64.7 ± 8.0 y) adults participated in this repeated-measures design consisting of four overnight laboratory stays. Each night, participants completed baseline visual acuity, gait, and balance testing. After a 2-h sleep opportunity, they were awakened for 13 min into one of four lighting conditions: very dim white light (< 0.5 lux); dim white light (∼28.0 lux); dim orange light (∼28.0 lux); and white room-level light (∼200 lux). During this awakening, participants completed the same sequence of testing as at baseline. Low-contrast visual acuity significantly decreased with decreasing illuminance conditions (F(3,45) = 98.26, p < 0.001). Our a priori hypothesis was confirmed in that variation in stride velocity and center of pressure path length were significantly worse during the mid-sleep awakening compared to presleep baseline. Lighting conditions during the awakening, however, did not influence these parameters. In exploratory analyses, we found that over one-third of the tested gait and balance parameters were significantly worse at the midsleep awakening as compared to baseline (p < 0.05), and nearly one-quarter had medium to large effect sizes (Cohen d ≥ 0.5; r ≥ 0.3). Balance and gait are impaired during midsleep awakenings among healthy, late middle-aged and older adults. This impairment is not ameliorated by exposure to room lighting, when compared to dim lights.

The effect of high-intensity cycling training on postural sway during standing under rested and fatigued conditions in healthy young adults.

The purpose of this study was to investigate whether high-intensity cycling training leads to adapted responses of balance performance in response to exercise-induced muscle fatigue. Eighteen healthy adults were assigned to either 3-weeks (n=8, age 20.1±2.6years, height 177±5cm, mass 73.6±5.1kg) or 6-weeks (n=10, age 24.3±5.8years, height 179±6cm, mass 81.0±15.8kg) of high-intensity training (HIT) on a cycle ergometer. The centre of pressure (COP) displacement in the anteroposterior (COPAP) direction and COP path length (COPL) were measured before and after the first and final high-intensity training sessions. Pre-training, exercise-induced fatigue elicited an increase in COPAP (3-weeks; p=0.001, 6-weeks; p=0.001) and COPL (3-weeks; p=0.002, 6-weeks; p=0.001) returning to pre-exercise levels within 10-min of recovery. Following 3-weeks of training, significant increases in COPAP (p=0.001) and COPL (p=0.002) were observed post-fatigue, returning to pre-exercise levels after 15-min of recovery. After 6-weeks of training no significant increases in sway (COPAP; p=0.212, COPL; p=0.998) were observed following exercise-induced fatigue. In summary, 3weeks of HIT resulted in longer recovery times following fatigue compared to pre-training assessments. After 6weeks of HIT, postural sway following fatigue was attenuated. These results indicate that HIT could be included in injury prevention programmes, however, caution should be taken during early stages of the overreaching process.

Effects of a Task-Oriented Exercise Program on Balance in Patients with Hemiplegia Following Stroke

Background: One of the most common disabilities after stroke is impaired balance, so improving balance is essential for performing daily activities through rehabilitation. A task-oriented exercise program is an effective approach to improving balance. Objectives: The aim of this study was to investigate the effects of a task-oriented exercise program on balance in patients with hemiplegia following stroke. Methods: This randomized clinical trial was conducted between October 2015 and January 2016, and 20 Iranian patients with hemiplegia following stroke were randomly assigned to experimental (n = 10) and control groups (n = 10). The experimental group received a 4-week task-oriented exercise program, and the control group received 4-week conventional physiotherapy, respectively. The patients were evaluated before and after the exercise intervention. Clinical measures included the Berg Balance Scale (BBS) while laboratory measures included the plantar pressure distribution, the center of pressure path length (COP path length), and the center of pressure confidence ellipse area (COP area). Results: Significant improvement was observed in the BBS after completion of the exercise program in both the experimental and the control groups (50.51.08 and 46.83.96, P < 0.05, respectively). Significant improvement was showed in the COP path length andarea after the task-oriented exerciseprogram(171.1452.15and65.4469.79, P< 0.01, respectively). TheCOParea also improved after completion of conventional therapy (114.988.99, P < 0.05), but the COP path length in the conventional therapy group and the plantar pressure distribution in both groups were not improved significantly after treatment (P > 0.05). The BBS, COP path length, and COP area improved significantly in the experimental group compared to the control group following intervention (P < 0.05). Conclusions: Atask-oriented exercise programis associated with an improvement in balance in patients with hemiplegia following stroke.

Dynamic balance is impaired after a match in young elite soccer players

PurposeThe aim of this study is to assess the effect of actual match effort on dynamic balance abilities in young elite soccer players. MethodsSeventeen Under 15 male players who compete at national level participated in the study. Their dynamic balance was assessed by having them jump starting with both feet on the ground in a standing position and land on one foot only. Their vertical time to stabilization (vTTS) and postural sway were calculated before and after 35 min of an unofficial match. Postural sway was assessed on the basis of center-of-pressure (COP) trajectories. Parameters considered were sway area, COP displacements in the antero-posterior (AP) and medio-lateral (ML) directions and COP path length. ResultsAfter the match, a significant increase in vTTS (p = 0.007) COP path length (p = 0.001) and COP displacements in ML (p < 0.001) was observed. Such effects involve both non-dominant (vTTS, path length) and dominant limb (COP displacements). ConclusionsThe physical effort associated with the match induces significant impairments of players' dynamic balance abilities. On the basis of such findings, coaches might consider integrating training sessions with specific balance exercises as well as performing injury-prevention routines even when players are fatigued, to better adapt them to match conditions.