Harsimran S. Baweja

Processing of visual information compromises the ability of older adults to control novel fine motor tasks

We performed two experiments to determine whether amplified motor output variability and compromised processing of visual information in older adults impair short-term adaptations when learning novel fine motor tasks. In Experiment 1, 12 young and 12 older adults underwent training to learn how to accurately trace a sinusoidal position target with abduction–adduction of their index finger. They performed 48 trials, which included 8 blocks of 6 trials (the last trial of each block was performed without visual feedback). Afterward, subjects received an interference task (watched a movie) for 60xa0min. We tested retention by asking subjects to perform the sinusoidal task (5 trials) with and without visual feedback. In Experiment 2, 12 young and 10 older adults traced the same sinusoidal position target with their index finger and ankle at three distinct visual angles (0.25°, 1° and 5.4°). In Experiment 1, the movement error and variability were greater for older adults during the visual feedback trials when compared with young adults. In contrast, during the no-vision trials, age-associated differences in movement error and variability were ameliorated. Short-term adaptations in learning the sinusoidal task were similar for young and older adults. In Experiment 2, lower amount of visual feedback minimized the age-associated differences in movement variability for both the index finger and ankle movements. We demonstrate that although short-term adaptations are similar for young and older adults, older adults do not process visual information as well as young adults and that compromises their ability to control novel fine motor tasks during acquisition, which could influence long-term retention and transfer.

Validating the BTrackS Balance Plate as a low cost alternative for the measurement of sway-induced center of pressure

The BTrackS Balance Plate (BBP) is a low-cost force plate that provides objective balance assessment and true portability for the user. Given that this technology is relatively new, the purpose of the present study was to provide the first center of pressure (COP) validation of the BBP. Two BBP devices (one new and one used) were compared with a laboratory-grade force plate (LFP) during simultaneous collection of COP that was induced by an inverted pendulum device with human-like sway characteristics. The results of this study showed almost perfect agreement between the BBP devices and the LFP (ICC>0.999), as well as a high degree of BBP accuracy (<1% error magnitude) and precision (<0.2mm regression residuals). These results suggest the BBP can serve as an effective, low-cost solution for objective balance testing in the laboratory or clinic.

Combination of BTrackS and Geri-Fit as a targeted approach for assessing and reducing the postural sway of older adults with high fall risk

Atypically high postural sway measured by a force plate is a known risk factor for falls in older adults. Further, it has been shown that small, but significant, reductions in postural sway are possible with various balance exercise interventions. In the present study, a new low-cost force-plate technology called the Balance Tracking System (BTrackS) was utilized to assess postural sway of older adults before and after 90 days of a well-established exercise program called Geri-Fit. Results showed an overall reduction in postural sway across all participants from pre- to post-intervention. However, the magnitude of effects was significantly influenced by the amount of postural sway demonstrated by individuals prior to Geri-Fit training. Specifically, more participants with atypically high postural sway pre-intervention experienced an overall postural sway reduction. These reductions experienced were typically greater than the minimum detectable change statistic for the BTrackS Balance Test. Taken together, these findings suggest that BTrackS is an effective means of identifying older adults with elevated postural sway, who are likely to benefit from Geri-Fit training to mitigate fall risk.

A point of application study to determine the accuracy, precision and reliability of a low-cost balance plate for center of pressure measurement

Changes in postural sway measured via force plate center of pressure have been associated with many aspects of human motor ability. A previous study validated the accuracy and precision of a relatively new, low-cost and portable force plate called the Balance Tracking System (BTrackS). This work compared a laboratory-grade force plate versus BTrackS during human-like dynamic sway conditions generated by an inverted pendulum device. The present study sought to extend previous validation attempts for BTrackS using a more traditional point of application (POA) approach. Computer numerical control (CNC) guided application of ∼155u202fN of force was applied five times to each of 21 points on five different BTrackS Balance Plate (BBP) devices with a hex-nose plunger. Results showed excellent agreement (ICCu202f>u202f0.999) between the POAs and measured COP by the BBP devices, as well as high accuracy (<1% average percent error) and precision (<0.1u202fcm average standard deviation of residuals). The ICC between BBP devices was exceptionally high (ICCu202f>u202f0.999) providing evidence of almost perfect inter-device reliability. Taken together, these results provide an important, static corollary to the previously obtained dynamic COP results from inverted pendulum testing of the BBP.

Short-duration therapeutic massage reduces postural upper trapezius muscle activity.

Massage therapy has historically been used as a therapeutic treatment to help reduce pain and promote relaxation. The aim of this study was to investigate the effect of therapeutic massage on the upper trapezius muscles, which are commonly associated with increased muscle tension. This was a randomized crossover study. Seventeen healthy individuals (nine women; 24.5±4.0 years) participated in the study. All individuals participated in two sessions that were held 24u2009h apart. In one of the sessions, the participants received a moderate pressure massage applied to the shoulders and neck. In the other session, participants sat quietly. The order of the sessions was counterbalanced across participants. Muscle activity, as measured by surface electromyography, of the upper trapezius muscles was recorded. The amount of muscle activity change following massage was compared with the change in muscle activity following quiet sitting. Muscle activity of the upper trapezius reduced significantly (19.3%; P=0.004) following massage compared with muscle activity following quiet sitting (1.0%). Our findings suggest that short-duration moderate pressure massage leads to a reduction in upper trapezius muscle activity. This result has potential implications for clinical populations such as those with chronic neck pain.

Normative Data for the BTrackS Balance Test of Postural Sway: Results from 16,357 Community-Dwelling Individuals Who Were 5 to 100 Years Old

BackgroundnPostural sway is routinely assessed because increased postural sway is associated with poorer performance of activities of daily living, higher rates of residential care, and increased risk of falling. Force plate technology is one of the most sensitive and objective means of assessing postural sway in the clinic.nnnObjectivenThe aim of this study was to provide the first set of normative data for the BTrackS Balance Test (BBT) of postural sway.nnnDesignnThe design was descriptive and population based.nnnMethodsnBBT results from 16,357 community-dwelling individuals who were 5 to 100 years old were accumulated and assessed for effects of age, sex, height, and weight. Percentile rankings were calculated for significant groupings.nnnResultsnBBT results were dependent on age and sex but not height or weight. Therefore, percentile rankings were determined for male and female individuals in each age category, with no consideration of participant height or weight.nnnLimitationsnData were collected by third-party practitioners with various backgrounds in more than 50 locations across the United States and Canada. There was an imbalance in the sample sizes for age and sex groupings.nnnConclusionsnThe findings of this study represent the largest normative dataset ever published for postural sway results. Normative data on the BBT can assist in determining abnormalities in postural sway, which have been linked to negative clinical outcomes.

Postural sway normative data across the adult lifespan: Results from 6280 individuals on the Balance Tracking System balance test: BTrackS balance test normative data

Postural sway measured using force plate technology is a known risk factor for falls in older adults, but is currently underutilized due to the high cost and lack of portability issues associated with most force plate systems. The Balance Tracking System (BTrackS) is a new force plate that alleviates these barriers and has potential for widespread use. The present study provides important normative data for the BTrackS Balance Test of postural sway that improves its translational value to the field of gerontology.