Anterior Cruciate Ligament Reconstructed Patients Who Recovered Normal Postural Control Have Dissimilar Brain Activation Patterns Compared to Healthy Controls

Postural control, which is a fundamental functional skill, reflects integration and coordination of sensory information. Damaged anterior cruciate ligament (ACL) may alter neural activation patterns in the brain, despite patients’ surgical reconstruction (ACLR). However, it is unknown whether ACLR patients with normal postural control have persistent neural adaptation in the brain. Therefore, we explored theta (4–8 Hz) and alpha-2 (10–12 Hz) oscillation bands at the prefrontal, premotor/supplementary motor, primary motor, somatosensory, and primary visual cortices, in which electrocortical activation is highly associated with goal-directed decision-making, preparation of movement, motor output, sensory input, and visual processing, respectively, during first 3 s of a single-leg stance at two different task complexities (stable/unstable) between ACLR patients and healthy controls. We observed that ACLR patients showed similar postural control ability to healthy controls, but dissimilar neural activation patterns in the brain. To conclude, we demonstrated that ACLR patients may rely on more neural sources on movement preparation in conjunction with sensory feedback during the early single-leg stance period relative to healthy controls to maintain postural control. This may be a compensatory protective mechanism to accommodate for the altered sensory inputs from the reconstructed knee and task complexity. Our study elucidates the strategically different brain activity utilized by ACLR patients to sustain postural control.

Center of pressure-based postural sway differences on parallel and single leg stance in Olympic deaf basketball and volleyball players

In sports such as basketball and volleyball, loss of balance due to the inability to maintain body stability and lack of postural control adversely affect athletic performance. Deaf athletes appear to struggle with balance and postural stability problems. The purpose of this study was to examine postural sway values in parallel and single leg stance of Olympic deaf basketball and volleyball players and reveal differences between the branches. Twenty-three male athletes from the Turkish national deaf basketball (n= 11) and volleyball (n= 12) teams participated in the study. After anthropometric measurements, the subjects completed postural sway (PS) tests in parallel/single leg stances with open eyes and closed eyes on a force plate. PS parameters (sway path, velocity, and area) obtained from the device software were used for the statistical analysis. The Mann-Whitney U-test was used to compare differences in PS parameters between basketball and volleyball players, and the alpha value was accepted as 0.05. Volleyball players had significantly better results in parallel stance and dominant leg PS values than basketball players (P<0.05). There was no significant difference between the groups in nondominant leg PS values (P>0.05). We think that proprioceptive and vestibular system enhancing training practices to be performed with stability exercises will be beneficial in terms of both promoting functional stability and interlimb coordination. Trainers and strength coaches should be aware of differences in the postural control mechanism of deaf athletes.

Longitudinal Association of Executive Function and Balance in Community-Dwelling Older Adults

Declines in Executive Function (EF) are associated with balance in community-dwelling older adults with Mild Cognitive Impairment (MCI). While this has been examined in cross-sectional studies, no longitudinal studies describe change over time. The purpose of this study was to examine how performance on the components of the Short Physical Performance Battery (SPPB) are associated with EF in community-dwelling older adults who transition into MCI. This secondary data analysis employed eight years of data from the National Health and Aging Trends Study dataset (2011 – 2018) with 1,225 participants in all eight waves (balanced). EF was measured with the Clock Drawing Test and SPPB balance tests included side-by-side, semi-tandem, full tandem, and single leg stance with eyes open or closed. Longitudinal ordered logistic regression was used to examine associations between each balance measure and EF while controlling for comorbidity, function, depression, gender, age, and ethnicity. EF was significantly associated with tandem, semi-tandem, and single leg stance after controlling for covariates. One point increase in SPPB can reduce the risk of EF impairment by 8.2% (Odds Ratio (OR)=0.918, p&lt;0.001). Among SPPB components, semi-tandem (OR=0.468) and side-by-side (OR=0.472) were the strongest predictors of EF impairment. Declines in both EF and balance performance occurred over an eight-year period in adults. This may reflect common neural processes shared between the cognitive and motor areas of the central nervous system. Best practice suggests screening both balance (tandem, semi-tandem, or single leg stance) and EF in the clinical assessment of community-dwelling older adults.

Living in turbulent times

Spoken metaphors such as “unstable situation” document a conceptual association between physical instability and difficult situations. Drawing on research in embodied cognition and conceptual metaphor, the present research examined whether people’s somatic experience can influence their attitudes toward the current COVID-19 pandemic. The hypothesis is that inducing a sensorimotor state such as physical instability can activate the associated abstract concepts such as the feelings of instability during a public health crisis. In Experiment 1, participants who sat at a wobbly table and chair believed more in and had greater concern about the coronavirus disease than participants in a stable workstation. Using a different manipulation of physical instability and a more diverse sample, Experiment 2 found that participants who stood on one foot rather than two were more likely to worry about the pandemic. Experiment 3 examined consequential behavior that might follow from respondents’ COVID-19-related attitudes. The results showed that participants who adopted a single-leg stance rather than a double-leg stance donated more money to the coronavirus treatment acceleration program aiming to stabilize the virus situation. Taken together, these findings indicate that seemingly irrelevant physical experiences can skew people’s opinions on the COVID-19 pandemic, exerting potential downstream effects on their actual behavior.

The effect of an infra-acetabular screw for anatomically shaped three-dimensional plate or standard plate designs in acetabulum fractures: a biomechanical analysis

Background Various plate shapes and implant configurations are used for stabilization of acetabulum fractures via anterior approaches. Little is known about the biomechanical stability of a two-dimensionally shaped “conventional” plate (“J-Plate”—JP) in comparison to three-dimensionally shaped plate configurations (3DP). In addition, the augmentary effect of an infra-acetabular lag-screw (IACS) fixation for anterior column and posterior hemi-transverse acetabulum fractures has not been clarified in comparison of JP and 3DP constructs. This study analyzed the difference between the biomechanical stability of JP compared to 3DP and the role of an IACS in a standardized acetabular fracture model in a single-leg stance loading configuration. Methods In an artificial bone substitute pelvis model (Synbone© Malans, Switzerland), a typical and standardized fracture pattern (anterior column and posterior hemi-transverse) was created with osteotomy jigs. After anatomic reduction the stabilization was performed using JP or 3DP. Eight pelvises per group were axially loaded in a single-leg stance model up to 400 N. After the load cycle, an additional infra-acetabular screw was placed and the measurement repeated. Fragment displacement was recorded by an optical tracking system (Optitrack Prime 13®, Corvallis, USA). Results In the pure placement, 3DP provided significantly superior stability when compared to JP. Augmentation of JP by IACS increased the stability significantly, up to the level of 3DP alone, whereas augmentation of the 3DP did not result in further increase of overall stability. Conclusion The anatomically shaped plate alone provides a superior biomechanical stability in fixation of an anterior column and posterior hemi-transverse fracture model. In a JP fixation the augmentation by IACS provides similar strength as the anatomically shaped 3DP. By use of the anatomically shaped 3DP the need of a clinically risky application of IACS might be avoidable. Level of evidence IV, Experimental study.

Features of statographic indicators of patients with coxarthrosis before and after arthroplasty

Background. Degenerative diseases of the hip joints are accompanied not only by pain, but also by changes in the anatomical proportions of the joint. Hip replacement eliminates pain syndrome, in most patients the anatomical proportions of the joints are restored, but if the clinical outcome of arthroplasty can be assessed radiologically, the result of functional recovery is difficult to assess, especially in dynamics. Statographic research today is one of the main diagnostic methods to monitor the recovery of patients after orthopedic surgeries. Purpose: according to statographic studies to determine the parameters that reflect the functional ability of patients to maintain an upright posture and monitor their changes in the recovery process after hip replacement surgery. Materials and methods. We examined 50 patients with degenerative diseases of the hip joint before and after arthroplasty. Data from standard study protocols were analyzed. Results. Before the operation, the oscillation coefficient differs markedly from the norm for all types of stance. Six months after surgery, normalization of swing is observed at single and double leg stance on a healthy extremity, but for the prosthetic limb, the oscillation coefficient does not improve significantly. Before the operation in double leg stance, there was a shift of the center of mass towards a healthy limb, after 6 months the deviation is significantly reduced. At single leg stance, there is a noticeable shift of the body towards a healthy limb, which decreases after arthroplasty. After surgery, patients have a decrease in the deviation of the body backwards in all types of stance, as well as a decrease in the rotation of the body in single leg stance, the load on the operated limb increases. Conclusions. In patients with coxarthrosis, the support ability of the damaged limb is impaired, which is confirmed by the displacement of the center of mass towards a healthy limb, the load on the foot of the affected limb decreases, the ability to maintain balance is reduced in both double and leg single stance. Monitoring these parameters is a mean to control the restoration of the function of maintaining the balance in patients after hip arthroplasty.

The effects of single leg stance during daily toothbrushing on the balance skills of elderly adults

Background and Study Aim. It was aimed to measure the effects of single-leg stance on measuring the individual postural limits and balance skills of elderly adults. Material and Methods. The present study involved a total of 360 elderly adults aged between 70 and 80 years. The participants were divided into two groups as 187 individuals in experiment group (99 women / 88 men) and 173 individuals in control (94 women / 79 men). In measuring the risk of fall and balance skills, the Functional Reach Test, Timed up and go Test, and Single Leg Stance Test were used. The participants in experiment group were asked to stand on one foot for a total of 4 minutes (2 minutes in morning and 2 minutes in evening) every day while brushing their teeth for 50 weeks. Since the data showed normal distribution, the independent samples t-test was used in determining the intergroup difference, whereas the dependent sample t-test was used in determining the intragroup pretest-posttest difference. Results. It was determined that there was a significant relationship between elderly adults’ balance skills and 4-min/day single-leg stance practice (p<0.05). In all the tests, it was found that the balance skills of women and men have improved and men had better values in comparison to women. Conclusion. It is thought that, via simple procedures such as lifting up one foot while brushing the teeth, the balance skills of elderly adults can be improved, the risk of fall can be reduced. They can be supported in terms of living an independent life.

Comparison of Static Balance among Cricket, Badminton, Football and Track and Field Athletes

BACKGROUND The balance plays an indispensable role in many sports. Static balance is crucial for a postural control and has an exceptional effect on the performance of sports players and for injury prevention. Sports like cricket, football, track and field, and badminton requires static balance for the execution of a sports-specific skill. Single leg stance test was used to assess balance on a surface during a 30 sec single-leg standing posture with eyes open and eyes closed. The main goal of this study was to determine that, in which sport the static balance was more and in which sport the static balance was inferior. The objectives were to assess the static balance in cricket, badminton, track and field, football athletes and compare the static balance in all 4 sports [cricket, badminton, track and field, football] METHODS A total of one hundred and twenty - four athletes [124], cricket {N = 31}, football {N = 31}, badminton {N = 31}, track and field {N = 31} voluntarily participated in the study. Static balance was assessed by using single leg stance test with eyes open and eyes closed. RESULTS By comparing all sports, it showed that there was a statistically significant difference between cricket, football, badminton and track and field athletes in dominant and non - dominant leg with eyes open and eyes closed. With eyes open, a static balance was demonstrated superior in track and field followed by football, cricket and least in badminton players in the dominant leg and non-dominant leg. (P < 0.0001) Whereas, with eyes closed, comparing between sports individually, there showed no such significant difference between dominant and non-dominant leg. Static balance was superior in track and field followed by football, by cricket and least in badminton in dominant and non-dominant leg (P < 0.0001). CONCLUSIONS Track and field players did not differ in dominant and non-dominant legs. In contrast, badminton players displayed mediocre static balance with eyes open and football players displayed mediocre static balance with eyes closed. There was no significant difference between open and closed eyes. But the balance score showed superior balance in open eyes when compared with closed eyes. KEY WORDS Athletes, Static Balance, Single Leg Stance Test, Balance, and Sports Performance.

Reliability and minimal detectable change values for performance-based measures of physical functioning in the Canadian Longitudinal Study on Aging (CLSA)

BACKGROUND The aim of this study was to determine the relative and absolute reliabilities of five key performance-based measures of physical function in the Canadian Longitudinal Study on Aging (CLSA). METHODS An age-stratified sub-sample of 147 participants from the CLSA who were undergoing their 3-year data collection visit participated in two repeat visits (within one week). Participants underwent tests of grip strength, 4-metre gait speed, Timed Up and Go (TUG), chair-rise and single-leg stance (left, right, mean, maximum). Intra-class correlation coefficients (ICC), standard error of measurement (SEM) and minimal detectable change (MDC) values were calculated. RESULTS The relative reliability for grip strength was excellent (ICC = 0.95); the TUG and single-leg stance tests had good reliability (ICC = 0.80 or 0.78-0.82, respectively); gait speed and the chair-rise test had moderate reliability (ICC=0.64 for both) for participants overall. For participants between 50 and 64 years, TUG and gait speed had poor reliabilities (ICC = 0.38 or 0.33, respectively). For participants aged 75+ years, the single-leg stance had poor reliability (ICC=0.30-0.39). The MDC90 was about 6 kg for grip strength, 2.3 seconds for TUG, 0.2 metres/second for gait speed, 5.2 seconds for chair-rise, and ranged from 22.8 to 26.2 seconds for the single-leg stance. CONCLUSIONS Among community-dwelling Canadians &gt;50 years old, the reliabilities of the CLSA measures were moderate to excellent. The TUG and gait speed in the youngest age group, and the single-leg stance in oldest age group, showed poor reliability. MDC values can be used to interpret changes over time.