Dynamic Balance Tests Research Articles

Effects of wearing a head-mounted display during a standard clinical test of dynamic balance

BackgroundThe use of virtual reality (VR) in clinical settings has increased with the introduction of affordable, easy-to-use head-mounted displays (HMDs). However, some have raised concerns about the effects that HMDs have on posture and locomotion, even without the projection of a virtual scene, which may be different across ages. Research questionHow does HMD wear impact the kinematic measures in younger and older adults? MethodsTwelve healthy young and sixteen older adults participated in two testing conditions: 1) TUG with no HMD and 2) TUG with an HMD displaying a scene of the actual environment (TUGHMD). The dependent variables were the pitch, yaw, and roll peak trunk velocities (PTVs) in each TUG component, turning cadence, and the time to complete the TUG and its components – SIT-TO-STAND, TURN, WALK, and STAND-TO-SIT. ResultsWearing the HMD decreased turning cadence and pitch and yaw PTVs in all TUG components, decreased roll PTV in SIT-TO-STAND and TURN, and increased the time taken to complete all TUG components in all participants. Wearing the HMD decreased the pitch PTV in SIT-TO-STAND in older relative to younger adults.Wearing an HMD affected TUG performance in younger and older adults, which should be considered when an HMD is used for VR applications in rehabilitation. SignificanceOur findings highlight the importance of considering the physical effect of HMD wear in clinical testing, which may not be present with non-wearable VR technologies.

An Unbalance Optimization Method for a Multi-Stage Rotor Based on an Assembly Error Propagation Model

For the assembly of a multi-stage rotor, such as an aero-engine or gas turbine, the parts need to be assembled optimally to avoid excessive unbalance. We propose a method to optimize the unbalance of a multi-stage rotor during assembly. First, we developed an assembly error propagation model for a multi-stage rotor. The alignment process and distribution of the screw holes of the adjacent rotors was considered for the first time. Secondly, we propose a new assembly datum for unbalance optimization to ensure consistency with the actual conditions of a dynamic balance test. Finally, the unbalance optimization of a multi-stage rotor was achieved using a genetic algorithm, and the corresponding optimal assembly orientations of rotors at different stages were also identified. The results of the simulations showed that the assembly error propagation model had high accuracy and that the genetic optimization process had good convergence. The effect of unbalance optimization was also proven with experiments.

Performance on sit-to-stand tests in relation to measures of functional fitness and sarcopenia diagnosis in community-dwelling older adults

BackgroundThe sit-to-stand (STS) test has been deployed as surrogate measures of strength or physical performance in sarcopenia diagnosis. This study examines the relationship of two common STS variants – Five Times Sit-to-Stand Test (5TSTS) and 30 s Chair Stand Test (30CST) – with grip strength, muscle mass and functional measures, and their impact on sarcopenia prevalence in community-dwelling older adults.MethodsThis is a cross-sectional analysis of 887 community-dwelling adults aged ≥50 years. Participants completed a battery of physical fitness tests - 5TSTS, 30CST, grip strength, gait speed, Timed-Up-and-Go (TUG) for dynamic balance and six-minute walk test (6MWT) for cardiorespiratory endurance. Muscle mass was measured using multi-frequency segmental bioelectrical impedance analysis (BIA). We performed correlation analysis between STS performance and other fitness measures and muscle mass, followed by multiple linear regression for the independent determinants of STS performance.ResultsMean participant age was 67.3±7 years, with female predominance (72.9%). STS tests exhibited weak correlations with grip strength (30CST, r = 0.290; 5TSTS, r = − 0.242; both p< 0.01), and stronger correlations with gait speed (30CST, r = 0.517; 5TSTS, r = − 0.533; both p< 0.01), endurance (30CST, r = 0.558; 5TSTS, r = − 0.531; both p < 0.01) and dynamic balance (30CST, r = − 0.501; 5TSTS, r = 0.646; both p< 0.01). Muscle mass correlated with grip strength but not STS. In multiple regression analysis, all fitness measures were independently associated with 30CST performance. Performance in both STS tests remained independent of muscle mass. There was no significant difference in prevalence of possible sarcopenia diagnosis using grip strength or STS (30CST, 25.0%; 5TSTS, 22.1%; grip strength, 22.3%; p = 0.276). When both measures are used, prevalence is significantly higher (42.0%; p = 0.276). Prevalence of confirmed sarcopenia with inclusion of muscle mass was significantly lower using STS compared with grip strength (30CST, 4.6%; 5TSTS, 4.1% vs. grip strength, 7.1%; p< 0.05).ConclusionIn the sarcopenia construct, STS tests better represents muscle physical performance rather than muscle strength. Different subsets of population with possible sarcopenia are identified depending on the test used. The lack of association of STS performance with muscle mass results in a lower prevalence of confirmed sarcopenia compared with grip strength, but may better reflect changes in muscle quality.

The effects of additional cognitive and motor tasks on static and dynamic balance in school-age children

Aim: To evaluate the effects of dual-tasks on balance in school-age children aged 7-10 years.Materials and Methods: In the present study, 28 primary school children aged 7-10 years were included. Static and dynamic balances were evaluated separately without any additional task and also in the presence of additional cognitive and motor tasks. The Sharpened Romberg Test and the One-Leg Stance Test were used to evaluate the static balance. The Five-Repetition Sit-To-Stand Test was used to evaluate dynamic balance. As a cognitive additional task, the children were asked to say Yes when they saw the red card and No when they saw the blue card. The motor additional task was designated as catching a ball.Results: In the static balance tests, the scores performed in the presence of an additional cognitive task were higher than those obtained without any additional task. However, this difference was not statistically significant (p>0.05). Test scores obtained with an additional motor task were significantly lower than those obtained without any additional task (p<0.001). In the Five-Repetition Sit-to Stand Test, the scores obtained in the presence of additional cognitive (p = 0.003) and motor (p = 0.002) tasks were significantly higher than those obtained without any additional task.Conclusion: In our study, an additional motor task performed simultaneously with static balance tests negatively affected balance performance in children aged 7-10 years. Postural control also reduced by additional motor or cognitive tasks during the dynamic balance tests. The results obtained in this study will contribute to understanding the relationship between cognition and balance system in children.

The effect of diurnal rhythms on static and dynamic balance performance

Abstract Study aim: The purpose of this research was to examine the effects of different times of day on static and dynamic balance performance. Material and methods: Thirty male individuals (age 22 ± 1.2 years, BMI 23.4 ± 1.3 kg/m2, height 178.5 ± 6.52 cm) volunteered for the study. The participants performed static and dynamic balance tests at 10:00, 15:00, and 20:00. Static and dynamic balance were measured using Y Balance Test (YBT) and the Balance Error Scoring System (BESS). One-factor repeated measures ANOVA with the LSD post-hoc procedure was performed to examine balance changes in the morning, afternoon, and evening. Results: Results indicated a significant difference in static balance scores at different times of day (p &lt; 0.05). Post-hoc analysis indicates that mean of errors in afternoon exhibits significantly smaller than those of morning (p = 0.024), and evening (p = 0.029). Other results showed significant differences in dynamic balance at different times of day (p &lt; 0.05). Post-hoc analysis indicates that means of reaching distance in afternoon exhibits significantly larger than those of morning (p = 0.032), and evening (p = 0.026). Conclusions: The results provide strong evidence about the effect of different times of day on performance.

Strength and balance deficits affecting patient satisfaction with total knee replacements

PurposePatient satisfaction with total knee replacement has been commonly assessed with self-reported surveys. Up to 19% of patients were dissatisfied with total knee replacement outcomes; however, very little is known about their objective physical abilities. Restoring knee strength is crucial for an increase in functional abilities. Improved balance is an essentialmeasure of total knee replacement success. However, it is unknown how dissatisfied patients differ from satisfied ones with respect to strength and balance abilities. The purpose of this study was to examine how knee flexor and extensor strength and balance abilities differed for dissatisfied total knee replacement patients compared with satisfied patients and healthy controls.MethodsThe study involved 9 dissatisfied and 15 satisfied total knee replacement patients and 15 healthy controls. Participants performed isokinetic knee flexion and extension tests at 60°/s and 180°/s using an isokinetic dynamometer. Bilateral and unilateral static and dynamic balance trials employed a Biodex Balance System. Stair ascent/descent tests and a chair rise test served to examine speed of activity.ResultsDissatisfied patients showed reduced peak extension (180°/s) and flexion (60°/s) torque compared with satisfied patients. No balance differences were evident, although an increased percentage of dissatisfied patients were unable to complete the static and dynamic unilateral balance tests. Stair ascent and descent times and pain levels were increased in the dissatisfied group.ConclusionsStrength increase may provide a more symmetrical movement pattern and better function. The inability to balance and longer functional test times indicate reduced functional ability and continuous pain.

The effect of teaching with slackline exercises on balance skills learning of university students

This study aims to analyze the impact of slackline exercises on the balance skills of university student on their learning. Twenty university student kickboxers voluntarily attended the study (8 women and 12 men). They were randomly divided into two groups (each group four females and six males) as the experimental group (EG) and the control group (CG), each consisting of 10 subjects. CG only followed regular training, while EG applied supervised slackline exercises for two days a week and 10 min sessions in addition to regular training for 4-week. Some tests were done before and after slackline exercises in the evaluation of all participants: counter movement jump, standing long jump, leg strength test, back strength test, static balance test “Stork Stand Balance” (SST) and dynamic balance test. According to the post-test results, the SST values which are the static balance test of EG were significantly higher than the CG. As a result, if slackline exercises, which are organized in addition to the regular training sessions specific to the branch, are applied in more extended periods, it can contribute to the balance skill learning and the balance necessary for performing technical movement.

Best Quantitative Tools for Assessing Static and Dynamic Standing Balance after Stroke: A Systematic Review.

Purpose: Our objective was to examine the psychometric qualities (reliability and validity) and clinical utility of quantitative tools in measuring the static and dynamic standing balance of individuals after stroke. Method: We searched four databases (PubMed/MEDLINE, PEDro, Embase, and CINAHL) for studies published from January 2018 through September 2019 and included those that assessed the psychometric properties of standing balance tests with an adult stroke population. We evaluated the quality of the studies using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist and assessed each test on a utility assessment scale. Results: A total of 22 studies met the inclusion criteria, and 18 quantitative tools for assessing static or dynamic standing balance of individuals with stroke were analyzed. Findings support good or excellent reliability for all tests, whereas correlations for validity ranged from weak to strong. Study quality was variable. Dynamic balance tests had better clinical utility scores than static ones. Five tests had complete psychometric analyses: quiet standing on a force platform, five-step test, sideways step, step length, and turn tests.

Estimativa do torque muscular de extensores do joelho de idosos baseado em testes de desempenho físico funcional

Objetivo: Verificar quais métodos de avaliação clínicos de força e potência muscular, e testes de desempenho físico funcionais estão correlacionados com o pico de torque isométrico e dinâmico dos extensores de joelho, e desenvolver equações preditivas que estimem o pico de torque isométrico e dinâmico em pessoas idosas. Métodos: Foram selecionados 49 sujeitos (≥ 60 anos) de ambos os sexos. O pico de torque muscular isométrico (PTISO) e dinâmico concêntrico (PTCON) dos extensores da articulação do joelho do membro preferido foi avaliado através de dinamômetro isocinético no primeiro dia de avaliação. Quarenta e oito horas depois o teste força máxima (1-RM) unilateral do membro preferido foi executado na cadeira extensora, seguindo do teste de potência do membro superior com uma medicine ball de 2 kg (ABM-2). No terceiro dia foram avaliados o teste de equilíbrio dinâmico (time up and go), a capacidade de subir e descer escadas (separadamente), com estes três testes foi construído um índice funcional (IFUNC). Resultados: Os principais resultados demonstraram que o IFUNC não prediz melhoria no pico de torque extensor do joelho (p0,05). Contrapondo a hipótese inicial que alterações no desempenho do pico de torque, tanto isométrico, como dinâmico, teria uma resposta direta com o desempenho funcional. Conclusão: As medidas de força máxima para membro inferior (cadeira extensora-1-RM) e potência de membro superior (arremesso da bola de medicine ball 2-kg) quando associadas explicam com mais de 60% (p0,05) uma mudança no desempenho na força isométrica e dinâmica dos extensores de joelho de idosos não treinados.

The Effect of Acute Caffeine Ingestion on Cognitive Dual Task Performance during Assessment of Static and Dynamic Balance in Older Adults.

The present work aimed to evaluate the effect of 3 mg·kg−1 caffeine consumption on the standing and dynamic balance performance of older adults and sought to establish if caffeine ingestion can modulate the influence of a cognitive dual task on balance performance. Twelve apparently healthy participants (8 females) aged >65 years (72 ± 3.7 years) completed the study. Bipedal postural sway, four square step test, timed up and go, Y-balance (anterior reach only) and force-time characteristics of sit-to-stand performance were used to assess standing and dynamic balance. Attention and working memory were assessed using a serial 3s and 7s subtraction task during seated rest and completion of the bipedal standing assessment and Y-balance test. This battery of assessments was completed on two separate occasions, once following the consumption of a non-ergogenic placebo and again following the consumption of 3 mg·kg−1 caffeine. The administration of treatments was randomised, counterbalanced and double-blind. Caffeine reduced performance in the bipedal standing balance assessments, evidenced by an increase in COPML, COPPath, COPVelocity. Performance during the dynamic balance tests was unaffected, other than rate of force development during the sit-to-stand, which was improved following caffeine ingestion. The introduction of a cognitive dual task had either limited effects, or improved facets of bipedal standing balance, whilst performance during the dynamic balance task was significantly reduced. In both balance assessments, there was evidence for a reduction in the performance of the cognitive task when both the balance and cognitive tests were performed simultaneously, with this effect not modulated by caffeine consumption. These findings refute the idea that caffeine ingestion may have positive effects on balance performance. However, despite a caffeine-induced reduction in bipedal standing balance, it is unlikely that caffeine ingestion would exacerbate fall risk given the limited effects in the dynamic balance tests. Future work should establish if these effects are generalisable to older frail participants and if caffeine can modulate the detrimental effects of an acute exercise bout on balance performance.

The Effects of Aquatic Versus Kata Techniques Training on Static and Dynamic Balance in Children with Autism Spectrum Disorder.

The present study aimed to compare the effect of a land-based and a swimming-based exercise program on balance abilities in children with autism. Thirty children were voluntarily selected and randomly assigned to karate exercise, aquatic training and control groups. Participants practiced for 10weeks, 2 sessions of 60min per week. Before and after the 10-week intervention, static and dynamic balance tests were administered. The results showed that both interventions had a significant effect on balance abilities (p < 0.001); interestingly, we found the greater improvement in balance performance in kata techniques group. Due to the importance of balance performance on daily functions, communication and interaction skills, karate and swimming exercises can be the valuable interventions added to autism's daily programs. Iranian Registry of Clinical Trials number: IRCT20180626040242N1.

Kontribusi Kondisi Fisik Terhadap Kemampuan Servis Bawah Dalam Permainan Bolavoli

This type of descriptive research which is contributive which aims to determine the strength of the arm muscles, hand eye coordination and balance of the ability to serve under volleyball in students of SMP Negeri 2 Balocci, Pangkep Regency. Student population of SMP Negeri 2 Balocci, Pangkep Regency, as many as 30 samples. The data were collected using the arm muscle strength test instrument (Push Up per 30 seconds), hand eye coordination test, dynamic balance test and volleyball under-serve ability test. The results of the study: 1) There is a significant and linear contribution of arm muscle strength to the ability to serve under volleyball of = 44.70% with a regression coefficient of α = 0.344 (P = 0.000). 2) There is a significant and linear hand-eye coordination contribution to the ability to serve under volleyball by 31.80% with a regression coefficient of α = 0.735 (P = 0.000). 3) There is a significant and linear balance contribution to the ability to serve under volleyball of = 55.20% with a regression coefficient of α = 0.140 (P = 0.000). 4) There is a significant and linear contribution of the combination of arm muscle strength, hand eye coordination, and balance to the ability to serve under volleyball by 98.90% with F = 795,684 (P = 0,000) and the regression equation Y = 17.304 + 0.344 X1 + 0.727 X2 - 0.133 X3.

Evaluation of balance in children with sensorineural hearing loss according to age

PurposeHearing is an important sensory skill for psychomotor development. As the cochlea and vestibule share the membranous labyrinth of the inner ear, children with sensorineural hearing loss (SNHL) may have vestibular dysfunction. This study aimed to evaluate static, dynamic, functional balance, and mobility as a whole in children with SNHL. Material and methodsEighty children, 40 with bilateral severe-to-profound SNHL (20 children between the ages of 6–10 were included in the Group 1, and 20 children between the ages of 11–15 were included in the Group 2) and 40 with normal-hearing (the Group 3 included 20 children between the ages of 6–10 and the Group 4 of 20 children between the ages of 11–15) were included in the study. The Single-Leg Stance (SLS) Test, Functional Reach Test (FRT), Time Up and Go (TUG) Test, and Pediatric Balance Scale (PBS) were used to evaluate the balance skills of children. ResultsThe present study found out that children with SNHL in both age groups performed worse than those with normal-hearing in FRT, SLS, and PBS. In the TUG test, children with SNHL in the younger age group had lower performance compared to their peers with normal-hearing while the TUG performance of children with SNHL in the older age group was similar to their normal-hearing peers. ConclusionIt was concluded that the static, dynamic and functional balance skills of children with SNHL were impaired compared to their normal-hearing peers. Including balance assessment in the routine test battery in children with SNHL may be decisive for early diagnosis and rehabilitation of balance disorders. It may be beneficial to add static, dynamic and functional balance tests to the test battery in addition to mobility assessment, especially in children with SNHL in the older age groups.

Applying the Minimal Detectable Change of a Static and Dynamic Balance Test Using a Portable Stabilometric Platform to Individually Assess Patients with Balance Disorders.

Balance disorders have a high prevalence among elderly people in developed countries, and falls resulting from balance disorders involve high healthcare costs. Therefore, tools and indicators are necessary to assess the response to treatments. Therefore, the aim of this study is to detect relevant changes through minimal detectable change (MDC) values in patients with balance disorders, specifically with vertigo. A test-retest of a static and dynamic balance test was conducted on 34 healthy young volunteer subjects using a portable stabilometric platform. Afterwards, in order to show the MDC applicability, eight patients diagnosed with balance disorders characterized by vertigo of vestibular origin performed the balance test before and after a treatment, contrasting the results with the assessment by a specialist physician. The balance test consisted of four tasks from the Romberg test for static balance control, assessing dynamic postural balance through the limits of stability (LOS). The results obtained in the test-retest show the reproducibility of the system as being similar to or better than those found in the literature. Regarding the static balance variables with the lowest MDC value, we highlight the average velocity of the center of pressure (COP) in all tasks and the root mean square (RMS), the area, and the mediolateral displacement in soft surface, with eyes closed. In LOS, all COP limits and the average speed of the COP and RMS were highlighted. Of the eight patients assessed, an agreement between the specialist physician and the balance test results exists in six of them, and for two of the patients, the specialist physician reported no progression, whereas the balance test showed worsening. Patients showed changes that exceeded the MDC values, and these changes were correlated with the results reported by the specialist physician. We conclude that (at least for these eight patients) certain variables were sufficiently sensitive to detect changes linked to balance progression. This is intended to improve decision making and individualized patient monitoring.

THE EFFECTS OF DIFFERENT GYMNASTICS TRAININGS ON BODY COMPOSITION AND SOME PERFORMANCE COMPONENTS IN ADULT MALE NON-GYMNASTS

The aim of this study was to compare the effects of artistic and trampoline gymnastics training on body composition and some of the physical fitness components in adult non-gymnasts. Forty-eight adult non-gymnasts were randomly assigned to three groups: a trampoline gymnastics group (TG) (n = 16), an artistic gymnastics group (AG) (n = 16), and a control group (CG) (n = 16). Two of the group except the CG performed different gymnastics training, including artistic and trampoline gymnastics twice a week during 12 weeks. The control group performed only a warm-up exercise twice a week along the study. To determine the effects of each gymnastics training on body composition, Y dynamic balance test that including six postural tasks, vertical jump, standing long jump and two different flexibility tests, were performed before and after the study for all groups. The AG and TG were significantly (p&lt;0,05) improved when it comes to all bio-motor abilities in adult non-gymnasts after 12 weeks of training. But the trampoline gymnastics exercises may be seen to be more efficient compared to the artistic gymnastics exercises. The trampoline exercises may be recommended as an alternative mode of exercise for improving bio-motor abilities.

Effects of Lower-Body Muscular Fatigue on Vertical Jump and Balance Performance.

Cooper, CN, Dabbs, NC, Davis, J, and Sauls, NM. Effects of lower-body muscular fatigue on vertical jump and balance performance. J Strength Cond Res 34(10): 2903-2910, 2020-Lower-body fatigue can lead to a decline in vertical jump (VJ) and balance performance due to decreased motor control and coordination. The purpose is to determine the effects of lower-body fatigue on VJ and balance performance. Twenty-four recreationally trained individuals participated in a single 1-hour familiarization and testing session. Participants were familiarized with balance, countermovement vertical jump (CMVJ), and static vertical jump (SVJ) using the Vertec. Three trials of static and dynamic balance tests were completed. Three trials of a SVJ and CMVJ were completed in a randomized order pre/post fatigue protocol. Three trials of double-leg and single-leg tests were performed. Dependent t tests analyzed differences between pre/post fatigue protocol for jumping and balance measures. There was a significant (p < 0.001) difference between pre/post measures for SVJ-H (height), CMVJ-H, and CMVJ peak power (PP). Results showed an interaction (p < 0.05) for group by time for CMVJ-H, CMVJ-peak force (PF), SVJ-PF, and SVJ-PP. There were no main effects (p > 0.05) for time or group for SVJ-rate of velocity development and SVJ-impact force (IF). There were no interactions, time effects, and group effects for balance variables (p > 0.05). Bosco protocol decreased VJ height and PF in SVJ, and VJ height and PF, IF, peak velocity, and PP for CMVJ potentially due to decreased muscle control, coordination, and force-generating capacity after fatigue. Practitioners should consider fatiguing effects on individuals performing jumping motions but it seems that fatigue has no effect on balance.

Research on vibration elimination of a 350 MW heat supply unit during cold start

A 350MW heat supply unit in a power plant encountered abnormal vibration of IP rotor bearing during cold start after overhaul. By analyzing the vibration data in the start-up process, the reason for abnormal vibration was found out to be excessive vibration of IP rotor passing through critical speed and rubbing between IP rotor and casing. Through the field high dynamic balancing test and adopting the most suitable operation control mode of this type of heat supply unit, the abnormal vibration of the unit was eliminated.

The interrater reliability of dynamic leap and balance test in healthy and chronic ankle instability.

The primary aim of this study was to assess the interrater reliability of the Dynamic Leap and Balance Test (DLBT) in chronic ankle instability (CAI) and healthy groups. The secondary aim was to assess the differences in errors and time taken to complete the DLBT between the two groups for both raters and to identify cutoff scores to distinguish between patients with CAI and healthy controls. This was a controlled laboratory reliability analysis study. Fourteen healthy college-aged subjects (9 women 5 men; weight=62.10±8.03; height=168.35±6.0) and sixteen with a history of CAI (9 women, 7 men; weight=68.01±10.74; height=172.08±11.37) participated. Interrater reliability was determined by independent raters for both total time taken to complete the task and errors made. The most optimal score to discriminate between two groups was determined by receiver operator curve analysis. Total time taken and errors made were also documented for group differences as secondary analysis. A strong agreement was found between the two raters for time and errors with intraclass correlation coefficient >0.80. Significantly (P<.05) higher number of errors were made and greater time taken by the CAI subjects when compared with healthy for both raters. The most optimal score to discriminate between CAI and healthy control was 43.28s and 4 errors. Excellent interrater reliability substantiates that it can be used confidently by different clinicians for testing dynamic balance. CAI group took more time and made more errors to complete the DLBT.

EFFECTS OF FULL IMMERSION VIRTUAL REALITY TRAINING ON BALANCE AND KNEE FUNCTION IN TOTAL KNEE REPLACEMENT PATIENTS: A RANDOMIZED CONTROLLED STUDY

Background: Recently, new methods have emerged that encourage voluntary participation by allowing patients to perform tasks, including exercises or treatments, in a virtual reality (VR) environment. Aim: This study aimed to examine the effects of full immersion virtual reality training on balance and knee function in patients who had undergone total knee replacement. Design: Single blind randomized controlled trial. Setting: Department of Physical Therapy in a rehabilitation center. Population: A total of 30 elderly patients ([Formula: see text]65 years old) who had undergone total knee replacement. Methods: Participants were randomly allocated to an experimental group ([Formula: see text]) and a control group ([Formula: see text]). The experimental group received with a continuous passive motion machine, exercise therapy, and a full immersion VR training program; the control group received only with a continuous passive motion machine and exercise therapy. Biorescue was used to test static and dynamic balance ability, and the Timed Up and Go and Western Ontario and McMaster Universities tests were used to assess knee function. Paired [Formula: see text]-tests were used to examine differences by time in each group, and independent [Formula: see text]-tests were used to examine differences between the groups. Results: In terms of within-group differences by time, both the experimental group and the control group showed significant changes in the anterior, and posterior limits of stability in both sides; static balance; and knee function. In the between-groups comparison, among static balance tests, there was a significant difference in center of mass path length in the standing position with eyes open ([Formula: see text]); among dynamic balance tests, there were significant differences in left, right, anterior, and posterior limits of stability ([Formula: see text]). Conclusions: VR training produced better early balance ability and knee function than what was seen in the control group. We believe that VR training in initial post-operative rehabilitation of total knee replacement patients may increase the rate of recovery. Clinical Rehabilitation Impact: VR exercise programs are effective in early rehabilitation after total knee replacement, and have clinical value as inexpensive methods that can promote active participation.

Effects of Short-Term Core Stability Training on Dynamic Balance and Trunk Muscle Endurance in Novice Olympic Weightlifters.

Our primary objective was to investigate the effects of short-term core stability training on dynamic balance and trunk muscle endurance in novice weightlifters learning the technique of the Olympic lifts. Our secondary objective was to compare dynamic balance and trunk muscle endurance between novice and experienced weightlifters. Thirty novice (NOV) and five experienced (EXP) weightlifters participated in the study. Mediolateral (ML) and anteroposterior (AP) dynamic balance and trunk muscle endurance testing were performed a week before (Pre) and after (Post) a 4-week core stability training program. In the NOV group, there was an improvement of both dynamic balance (ML and AP, p = 0.0002) and trunk muscle endurance (p = 0.0002). In the EXP group, there was no significant difference between Pre and Post testing conditions, except an increase in muscle endurance in the right-side plank (p = 0.0486). Analysis of the results showed that experienced lifters were characterized by more effective dynamic balance and greater core muscle endurance than their novice peers, not only before the training program but after its completion as well. In conclusion, the applied short-term core stability training improved dynamic balance and trunk muscle endurance in novice weightlifters learning the Olympic lifts. Such an exercise program can be incorporated into a training regime of novice weightlifters to prepare them for technically difficult tasks of the Olympic snatch and clean and jerk.