Association of activities of daily living, mobility and balance ability, and symptoms of Parkinson's disease with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in patients with Parkinson's disease.

PURPOSE: We examined the association of activities of daily living (ADL), mobility and balance ability, and symptoms of Parkinson's disease (PD) with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in patients with PD. METHODS: The subjects were 11 community-dwelling patients with PD. ADL were assessed using the Functional Independence Measure. Mobility capacity was assessed based on measurement of maximal walking speed and timed up-and-go time, while balance ability was evaluated based on measurement of one-legged stance time. The symptoms of PD were assessed based on measurement of the Hoehn and Yahr stage and Unified Parkinson's Disease Rating Scale. Muscle thickness (MT) and echo intensity (EI) of the trunk and lower extremity muscles were also measured using an ultrasound imaging device. RESULTS: Partial correlation analysis revealed an association between reduced ADL and increased EI of the lumbar erector spinae muscle; reduced mobility capacity and increased EI of the rectus abdominis and gluteus minimus muscles; and reduced balance ability and decreased MT of the lumbar erector spinae muscle and increased EI of the lumbar erector spinae, semitendinosus, and tibialis posterior muscles. Partial correlation analysis also showed an association between symptoms of severe PD and decreased MT of the tibialis anterior muscles and increased EI of the lumbar erector spinae, gluteus minimus, and tibialis posterior muscles. CONCLUSION: The properties of the trunk and lower extremity muscles may be critical for ADL, mobility and balance ability, and symptoms of PD in patients with PD.

Association of activities of daily living and cognitive function with thickness of the upper extremity muscles in children and adults with cerebral palsy.

PURPOSE: We examined the association of activities of daily living (ADL) and cognitive function with the upper extremity muscle thickness and upper extremity range of motion (ROM) and spasticity in children and adults with cerebral palsy (CP). METHODS: The subjects were 20 children and adults with CP. The ADL performed using the upper extremities and cognitive function were assessed using the self-care domain of the Pediatric Evaluation of Disability Inventory (PEDI) and the full-scale intelligence quotient (FSIQ) of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV), respectively. The WISC-IV was assessed in only seven of 20 subjects able to undergo evaluation. The thickness of the upper extremity muscles was measured using an ultrasound imaging device. Moreover, ROM and spasticity of the upper extremities were assessed using the Modified Ashworth Scale (MAS). Manual manipulation ability was also assessed using the Manual Ability Classification System (MACS). RESULTS: Stepwise regression analysis revealed that the extensor digitorum muscle thickness and MACS level were significant and independent factors of self-care in the PEDI. Partial correlation analysis with MACS level and age as control variables showed that the FSIQ of the WISC-IV was significantly associated with the thickness of the anterior fibers of the deltoid and flexor digitorum superficialis muscles. CONCLUSION: Reduced ADL performed using the upper extremities is associated with decreased extensor digitorum muscle thickness rather than ROM and spasticity of the upper extremities in children and adults with CP.

Association of gross motor function and activities of daily living with muscle mass of the trunk and lower extremity muscles, range of motion, and spasticity in children and adults with cerebral palsy.

PURPOSE: We examined the association of gross motor function and activities of daily living (ADL) with muscle mass of the trunk and lower extremity muscles in children and adults with cerebral palsy (CP). METHODS: The subjects were 32 children and adults with CP. Muscle thickness of the trunk and lower extremity muscles was measured using an ultrasound imaging device. RESULTS: Stepwise regression analysis revealed that the thoracic erector spinae muscle thickness was a significant and independent factor of gross motor function. Stepwise regression analysis also showed that the thickness of the rectus abdominis and vastus lateralis muscles were significant and independent factors of ADL. CONCLUSIONS: Our findings suggest that declined gross motor function is associated with decreased thoracic erector spinae muscle mass in children and adults with CP. The results also indicate that declined ADL is associated with decreased muscle mass of the rectus abdominis and vastus lateralis muscles.

Association of sagittal spinal alignment in the standing position with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in patients with Parkinson's disease.

BACKGROUND: We examined the association of sagittal spinal alignment in the standing position with the masses and amounts of intramuscular non-contractile tissue of multiple trunk and lower extremity muscles, such as the hip joint muscles, measured using an ultrasound imaging device in patients with Parkinson's disease (PD). METHODS: The participants were 10 patients with PD. Sagittal spinal alignment (thoracic kyphosis, lumbar lordosis, and sacral anterior inclination angles) in the standing position was measured using a Spinal Mouse. Muscle thicknesses and echo intensities of the trunk and lower extremity muscles, including the hip joint muscles, were also measured in the prone or supine position using an ultrasound imaging device. FINDINGS: Partial correlation analysis with body height and weight as control variables showed that a low lumbar lordosis angle in the standing position was significantly associated with low thicknesses of the trunk extensor muscles (lumbar erector spinae and multifidus). Partial correlation analysis also revealed that a high sacral anterior inclination angle in the standing position was significantly associated with low lumbar multifidus muscle thickness. However, the thicknesses and echo intensities of the trunk flexor and hip joint muscles were not significantly related to thoracic kyphosis, lumbar lordosis, or sacral anterior inclination angles. INTERPRETATION: The results of this study suggested the association between a low lumbar lordosis angle in the standing position and low lumbar erector spinae and multifidus muscle thicknesses and between a high sacral anterior inclination angle in the standing position and low lumbar multifidus muscle thickness in patients with PD.

Comparison of the mass and amount of intramuscular non-contractile tissue of the trunk and lower extremity muscles between patients with Parkinson's disease and community-dwelling older adults.

OBJECTIVE: This study compared the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles, sagittal spinal alignment, and mobility and balance ability between patients with Parkinson's disease (PD) and older adults. METHODS: This study included 26 older adults (control [CTR] group) and eight patients with PD (PD group). Muscle thicknesses and echo intensities of the trunk and lower extremity muscles were measured using an ultrasound imaging device. Sagittal spinal alignments in the standing and prone positions were assessed using a Spinal Mouse. Mobility capacity was assessed based on the measurements of usual and maximal walking speeds, timed up-and-go (TUG) time, and five-chair-stand time, while balance ability was assessed based on the measurement of one-legged stance (OLS) time. RESULTS: Our results showed significantly lower gluteus maximus and tibialis anterior muscle thicknesses, higher thickness of the short head of the biceps femoris muscle, and higher echo intensity of the gluteus maximus muscle in the PD group than in the CTR group. Lumbar lordosis angle in the standing position, usual and maximal walking speeds, and OLS time were significantly lower, while the TUG and five-chair-stand times were significantly higher in the PD group than in the CTR group. The other factors did not differ significantly between groups. CONCLUSIONS: Our results revealed lower masses of the gluteus maximus and tibialis anterior muscles, higher mass of the short head of the biceps femoris muscle, and higher amounts of intramuscular non-contractile tissue of the gluteus maximus muscle in patients with PD.

Coexistence of Low Back Pain and Lumbar Kyphosis and the Association With Increased Functional Disability in Knee Osteoarthritis: Results From a Population-Based Cohort.

OBJECTIVE: To examine the association of low back pain (LBP) and lumbar kyphosis with functional disabilities and knee symptoms in patients with knee osteoarthritis (OA). METHODS: We analyzed 586 participants (80.1% female; mean ± SD age 68.8 ± 5.2 years) from the Nagahama Study who were age ≥60 years and had radiographically confirmed knee OA. The Knee Society Knee Scoring System (KSS) was used to assess functional disabilities and knee symptoms. LBP was defined as the presence of any persistent back pain for more than 3 months. Lumbar kyphosis was determined by skin-surface methods using a computer-aided electronic device called the Spinal Mouse. Multiple linear regression analysis was used for assessing the association of LBP and lumbar kyphosis with the KSS scores. Subgroup analyses based on sex were also performed. RESULTS: LBP and lumbar kyphosis were independently associated with a lower KSS function score after adjustment for covariates (mean difference -4.96 [95% confidence interval (95% CI) -7.56, -2.36] points for LBP alone, mean difference -4.47 [95% CI -8.51, -0.43] points for lumbar kyphosis alone, and mean difference -13.86 [95% CI -18.86, -8.86] points for the coexistence of LBP and lumbar kyphosis, respectively). The coexistence of LBP and lumbar kyphosis in women was associated with a lower KSS symptom score (mean difference -4.49 [95% CI -6.42, -2.55] points). CONCLUSION: These findings suggest that both LBP and lumbar kyphosis are useful clinical signals indicating functional disability and knee symptoms in patients with knee OA.

Comparison of the Upper and Lower Extremity and Trunk Muscle Masses between Children with Down Syndrome and Children with Typical Development.

PURPOSE: Comparison of not only the upper and lower extremity but also trunk muscle masses measured by means of an ultrasound imaging device between children with Down syndrome (DS) and children with typical development (TD). METHODS: The study included 35 children with TD (TD group) and 26 children with DS (DS group). The upper and lower extremity and trunk muscle thicknesses were measured using an ultrasound imaging device. RESULTS: The thicknesses of the rectus abdominis, obliquus externus and internus abdominis, rectus femoris, and short head of the biceps femoris muscles were significantly lower in the DS group than in the TD group. The thicknesses of the other upper and lower extremity and trunk muscles did not differ significantly between the groups. CONCLUSIONS: The results of this study demonstrated lower masses of trunk flexor and knee extensor and flexor muscles in children with DS compared to those in children with TD.

Adaptive feedforward control of closed orbit distortion caused by fast helicity-switching undulators.

A new correction algorithm for closed orbit distortion based on an adaptive feedforward control (AFC) has been developed. At SPring-8, two helicity-switching twin-helical undulators (THUs) had been implemented with conventional feedforward corrections. However, the validity of these corrections turned out to be expiring due to unforeseen variation in the error magnetic fields with time. The developed AFC system has been applied to the THUs dynamically updating the feedforward table without stopping the helicity switching amid user experiments. The error sources in the two THUs are successfully resolved and corrected even while the two THUs are switching simultaneously with the same repetition period. The actual operation of the new AFC system enables us to keep the orbit variations suppressed with an accuracy at the sub-micrometre level in a transparent way for light source users.

Association of sagittal spinal alignment in the sitting position with the trunk and lower extremity muscle masses in children and adults with cerebral palsy: A pilot study.

BACKGROUND: We examined the association of sagittal spinal alignment in the sitting position with the trunk and lower extremity muscle masses in children and adults with cerebral palsy (CP). We also compared muscle masses between children and adults with CP who could and could not sit without the support of their upper extremities. METHODS: The subjects were 34 children and adults with CP. Sagittal spinal alignment in the sitting position, such as thoracic kyphosis, lumbar lordosis, and sacral anterior inclination angles were measured using a Spinal Mouse. The thicknesses of the trunk and lower extremity muscles were measured using an ultrasound imaging device. Furthermore, the subjects were classified into the sitting-possible group (n = 18), who could sit without the support of the upper extremities, or a sitting-impossible group (n = 16), who could not sit without the support of the upper extremities. FINDINGS: Stepwise regression analysis revealed that the lumbar multifidus muscle thickness and body weight were significant and independent factors of the lumbar lordosis angle in the sitting position. The thicknesses of the thoracic erector spinae, gluteus maximus and minimus, long head of the biceps femoris, semitendinosus, and rectus femoris muscles were significantly lower in the sitting-impossible group than those in the sitting-possible group. INTERPRETATION: Decreased lumbar lordosis angle in the sitting position was associated with decreased lumbar multifidus muscle mass in children and adults with CP. Furthermore, not only trunk extensor but also hip joint muscles may contribute to sitting without upper extremity support.

Association of mobility capacity with the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles in community-dwelling older adults.

We examined the association of mobility capacity with muscle thicknesses and echo intensities of the trunk and lower extremity muscles measured using an ultrasound imaging device in community-dwelling older adults. The participants were 57 community-dwelling older adults. Mobility capacity was assessed based on the measurement of usual and maximal walking speeds and timed up-and-go (TUG) time. Muscle thickness and echo intensity of the trunk and lower extremity muscles were measured using an ultrasound imaging device. Finally, sagittal spinal alignment was assessed based on the measurement of thoracic kyphosis, lumbar lordosis, and sacral anterior inclination angles in the standing position using a Spinal Mouse. Stepwise regression analysis showed that the tibialis anterior muscle thickness, tibialis posterior muscle echo intensity, and body weight were significant and independent factors of usual walking speed, with a coefficient of determination (R2) of 0.25. The thicknesses of the thoracic erector spinae and obliquus externus abdominis muscles were significant and independent factors of maximal walking speed (R2 = 0.26). Moreover, only age was a significant and independent factor for TUG time (R2 = 0.10). The results of this study suggested associations 1) between slow usual walking speed and low tibialis anterior muscle thicknesses and high echo intensity of the tibialis posterior muscle and 2) between slow maximal walking speed and low thoracic erector spinae and obliquus externus abdominis thicknesses in community-dwelling older adults.

Comparison of the degree of pes planovalgus and muscle mass of the ankle joint and foot muscles between children with Down syndrome and children with typical development.

We aimed to compare the degree of pes planovalgus and muscle mass of the ankle joint and foot muscles between children with Down syndrome (DS) and children with typical development (TD). We also examined the association of the degree of pes planovalgus with muscle mass of the ankle joint and foot muscles in children with DS and children with TD. The subjects were 24 children with TD (control [CTR] group) and 23 children with DS (DS group). To assess pes planovalgus, the Arch Height Index (AHI) in the standing position was measured. Muscle thickness of the ankle joint and foot muscles was measured using an ultrasound imaging device. The AHI and thickness of the soleus and tibialis posterior muscles were significantly lower in the DS group than those in the CTR group. The thickness of the flexor digitorum longus muscle was significantly greater in the DS group than that in the CTR group. Stepwise regression analysis revealed that the thickness of the flexor digitorum longus muscle was a significant and independent factor of the AHI in children comprising the CTR and DS groups. The thickness of the flexor digitorum longus muscle increased with decreasing AHI. The results of this study suggest that the AHI and muscle mass of the soleus and tibialis posterior muscles decrease, while muscle mass of the flexor digitorum longus muscle increases in children with DS. The results also indicate that decreased AHI is associated with increased muscle mass of the flexor digitorum longus muscle in children.

Abdominal girth as an index of muscle tension during abdominal hollowing: Selecting the optimal training intensity for the transversus abdominis muscle.

The abdominal hollowing technique is used for training the transversus abdominis (TrA). However, the optimal intensity of hollowing is still unclear. The objective of the present study is to verify the validity of estimating the tension of the TrA by measuring the girth of the abdomen with a tape and to determine the optimum intensity of hollowing to effectively train the TrA. Sixteen healthy males performed hollowing with an intensity of 0%, 25%, 50%, 75%, and 100%, estimated from the girth of the abdomen. The shear elastic modulus was measured for the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and TrA at all intensities via ultrasonic shear wave elastography. The shear elastic modulus was considered as the index of the tension of the abdominal muscles at each intensity, and the ratio of the TrA to RA, EO, and IO respectively was calculated as the index of TrA selectivity. As the intensity of hollowing increased, the girth of abdomen decreased and tension of all the four muscles increased. The ratio of TrA to the RA, EO, and IO did not exhibit a significant variation among hollowing intensities of 25% to 100%. It is rational to estimate the tension of the TrA by measuring the girth of the abdomen. Moreover, considering both TrA contraction intensity and selectivity, abdominal hollowing performed at maximum intensity was effective for the maximum contraction training of the TrA.

The effect of combined transcranial direct current stimulation and peripheral nerve electrical stimulation on corticospinal excitability.

Transcranial direct current stimulation (tDCS) and peripheral nerve electrical stimulation (PES) can change corticospinal excitability. tDCS can be used to non-invasively modulate the cerebral cortex's excitability by applying weak current to an electrode attached to the head, and the effect varies with the electrode's polarity. Previous studies have reported the effect of combined tDCS and PES on corticospinal excitability; when compared to single stimulation, combined stimulation increases cortical excitability. In contrast, another study reported that the effect of tDCS is attenuated by PES; hence, there is no consensus opinion on the effect on combined stimulation. Therefore, this study aimed to clarify the effect of combined tDCS and PES on corticospinal excitability. In Experiment 1, the combined stimulation of anodal tDCS and PES (anodal tDCS + PES) was performed, and in Experiment 2, a combined stimulation with PES, after cathodal tDCS (PES after cathodal tDCS), was performed using a homeostatic metaplasticity theoretical model. In Experiment 1, anodal tDCS produced a significant increase from baseline in motor-evoked potential (MEP) amplitude 10 min after stimulation, but no significant changes in MEP amplitude were observed with PES or the anodal tDCS + PES condition. Experiment 2 showed a significant decrease in MEP amplitude immediately after cathodal tDCS, and a significant increase in MEP amplitude 15 min after PES, but no significant change in MEP amplitude was observed with sequential PES following cathodal tDCS. In conclusion, our data indicate that PES with anodal tDCS suppressed the effect of tDCS. Also, PES after cathodal tDCS did not induce homeostatic metaplasticity and increase corticospinal excitability.

Association of Pain History and Current Pain With Sagittal Spinal Alignment and Muscle Stiffness and Muscle Mass of the Back Muscles in Middle-aged and Elderly Women.

STUDY DESIGN: A cross-sectional study. OBJECTIVE: To investigate the association of low back pain history (LBPH) and LBP with sagittal spinal alignment, stiffness assessed using ultrasonic shear wave elastography, and mass of the back muscle in community-dwelling middle-aged and elderly women. SUMMARY OF BACKGROUND DATA: The association of LBPH and LBP with sagittal spinal alignment, stiffness, and mass of the back muscles remains unclear in middle-aged and elderly women. PARTICIPANTS AND METHODS: The study comprised 19 asymptomatic middle-aged and elderly women [control (CTR) group], 16 middle-aged and elderly women with LBPH (LBPH group), and 23 middle-aged and elderly women with LBP (LBP group). Sagittal spinal alignment in the standing and prone positions (kyphosis angle in the thoracic spine, lordosis angle in the lumbar spine, and anterior inclination angle in the sacrum) was measured using a Spinal Mouse. The stiffness of the back muscles (lumbar erector spinae and multifidus) in the prone position was measured using ultrasonic shear wave elastography. The mass of the back muscles (thoracic and lumbar erector spinae, lumbar multifidus, and quadratus lumborum) was also measured. RESULTS: Multiple logistic regression analysis with a forward selection method showed that the stiffness of the lumbar multifidus muscle was a significant and independent factor of LBPH. The stiffness of the lumbar multifidus muscle was significantly higher in the LBPH group than in the CTR group. Multiple logistic regression analysis also indicated that lumbar lordosis angle in the standing position was a significant and independent factor of LBP. The lumbar lordosis angle was significantly smaller in the LBP group than in the CTR group. CONCLUSIONS: Our results suggest that LBPH is associated with increased stiffness of the lumbar multifidus muscle in the prone position, and that LBP is associated with the decreased lumbar lordosis in the standing position in community-dwelling middle-aged and elderly women.

Effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and multifidus muscles: an ultrasonic shear wave elastography study.

PURPOSE: The present study aimed to clarify the effects of the trunk position on muscle stiffness that reflects elongation of the lumbar erector spinae and lumbar multifidus muscles using ultrasonic shear wave elastography (SWE). METHODS: The study included ten healthy men. The shear elastic modulus of the left lumbar erector spinae and lumbar multifidus muscles were evaluated using ultrasonic SWE. Measurement postures for the left lumbar erector spinae muscle were (1) prone position (Rest), (2) sitting position with the trunk flexed (Flexion), (3) the Flexion position adding right trunk lateral flexion (Flexion-Lateral Flexion), and (4) the Flexion position adding right trunk rotation (Flexion-Rotation 1). The left lumbar multifidus muscle were measured in positions (1)-(3), and (5) the Flexion position adding left trunk rotation (Flexion-Rotation 2). RESULTS: The shear elastic modulus of the lumbar erector spinae muscle in the Flexion-Lateral Flexion position was significantly higher than that in the Rest, Flexion, or Flexion-Rotation 1 positions. Shear elastic modulus of the lumbar multifidus muscle was similar in the Flexion, Flexion-Lateral Flexion, and Flexion-Rotation 2 positions, but significantly lower in the Rest position. CONCLUSIONS: The results of the present study suggest that the lumbar erector spinae muscle is stretched effectively in the position adding trunk contralateral lateral flexion to flexion. The results also indicate that the lumbar multifidus muscle, which does not appear to be affected by adding trunk contralateral lateral flexion or ipsilateral rotation to flexion, is stretched effectively in the trunk flexion position.

Small Degree of Lumbar Lordosis as an Overlooked Determinant for Orthostatic Increases in Blood Pressure in the Elderly: The Nagahama Study.

BACKGROUND: Orthostatic hypertension was associated with worse cardiovascular outcomes, although the factors responsible for an orthostatic rise in blood pressure (BP) are uncertain. We investigated a possible relationship between a stooping posture and orthostatic BP change. METHODS: Study participants consisted of 1,992 older individuals. Orthostatic BP change was calculated by systolic BP measured at sitting position, and again 1 and 3 minutes after standing up. Spinal alignment and curvature was assessed by guiding the SpinalMouse device on the surface of the skin along the spine. RESULTS: Mean lumbar lordosis at standing position was 13.4° ± 12.4°. The degree of lumbar lordosis was significantly smaller in orthostatic hypertensive individuals (systolic BP change, ≥+20 mm Hg: 3.3° ± 15.6°, ≥+10 mm Hg: 10.4° ± 14.3°) than in individuals who were orthostatic normotensive (14.2° ± 11.9°). Multiple linear regression analysis identified lumbar lordosis (ß = -0.171, P < 0.001) and thoracic kyphosis (ß = 0.062, P = 0.007), but not sacral inclination (ß = 0.033, P = 0.303), as independent determinants for orthostatic BP change. As waist circumference was another independent determinant, the frequency of orthostatic hypertensive individuals was linearly increased with the combination of abdominal obesity and small degree of lumbar lordosis (control: 9.9%, abdominal obesity: 17.4%, small degree of lordosis: 19.4%, both: 24.1%, P < 0.001). Participants who sustained orthostatic hypertension for 3 minutes after standing up had the smallest degree of lumbar lordosis (5.2° ± 16.4°). CONCLUSION: Stooped posture was an overlooked determinant for orthostatic increases in BP.

Back muscle activity and sagittal spinal alignment during quadruped upper and lower extremity lift in young men with low back pain history.

BACKGROUND: Quadruped upper and lower extremity lift (QULEL) is performed for selective training of the lumbar multifidus muscle in patients with low back pain (LBP) or individuals with LBP history (LBPH). However, the activities of the back muscles and sagittal spinal alignment during QULEL are not clarified in individuals with LBPH. RESEARCH QUESTION: This study aimed to analyze the activities of the back muscles and sagittal spinal alignment during QULEL in young male with LBPH. METHODS: The study comprised 9 asymptomatic young men and 8 young men with LBPH. The activities of the lumbar multifidus, latissimus dorsi and thoracic erector spinae, and lumbar erector spinae muscles were measured using surface electromyography. The flexion angles of the upper and lower thoracic spine, and extension angle of the lumbar spine were measured using a 6-DF electromagnetic motion tracking system. The association with LBPH was investigated using multiple logistic regression analysis with a forward selection method, with the activities of the back muscles, sagittal spinal alignment, age, body height, and body weight as independent variables. RESULTS: Multiple logistic regression analysis (p = 0.0002) showed that the activity of the latissimus dorsi and thoracic erector spinae muscles in the side on which the lower extremity was lifted and body height were significant and independent determinants of LBPH, but other factors were not. SIGNIFICANCE: The results of this study suggest that the activity of the latissimus dorsi and thoracic erector spinae muscles increases while there are no decrease in activity of the lumbar multifidus muscle and excessive extension of the lumbar spine during QULEL in young men with LBPH.

Effect of noisy galvanic vestibular stimulation in community-dwelling elderly people: a randomised controlled trial.

BACKGROUND: Balance disorders are a risk factor for falls in the elderly. Although noisy galvanic vestibular stimulation (nGVS) has been reported to improve balance in young people, randomised control trials targeting community-dwelling elderly people have not been conducted to date. We aimed to assess the influence of nGVS on COP sway in the open-eye standing posture among community-dwelling elderly people in a randomised controlled trial. METHODS: A randomised controlled trial of 32 community-dwelling elderly people randomly assigned to control (sham stimulation) and an nGVS groups. All participants underwent centre of pressure (COP) sway measurements while standing with open eyes at baseline and during stimulation. The control group underwent sham stimulation and the nGVS group underwent noise stimulation (0.4 mA; 0.1-640 Hz). RESULTS: In the nGVS group, sway path length, mediolateral mean velocity and anteroposterior mean velocity decreased during stimulation compared with baseline (P < 0.01). The effect of nGVS was large in participants with a high COP sway path length at baseline, but there was no significant difference in COP sway in the control group. CONCLUSIONS: We conclude that nGVS decreases the COP sway path length and mean velocity of community-dwelling elderly people when standing with open eyes. This suggests that nGVS could be effective for treating balance dysfunction in the elderly.

Transcranial Alternating Current Stimulation With Gamma Oscillations Over the Primary Motor Cortex and Cerebellar Hemisphere Improved Visuomotor Performance.

Transcranial alternating current stimulation (tACS) can be used to modulate oscillatory brain activity. In this study, we investigated whether tACS applied over the primary motor cortex (M1) and cerebellar cortex region improved motor performance. We applied tACS (1.0 mA) to 20 healthy adults while they performed an isometric force task with some visuomotor control using their right index finger. Gamma (70 Hz) oscillations in the Experiment 1 or beta (20 Hz) oscillations in the Experiment 2 were applied for 30 s over the left M1, right cerebellar hemisphere or both regions ("M1-Cerebellum"), and errors performing the task were compared. Beta-oscillation tACS did not affect motor performance. With the gamma-oscillation tACS, a negative correlation was found between the difference of error in the M1-Cerebellum condition and the number of errors in the sham condition (P = 0.005, Pearson's r = -0.597), indicating that motor performance improved with M1-Cerebellum tACS for subjects with low motor performance in the sham condition. Those who performed poorly in the sham condition made significantly fewer errors with M1-Cerebellum tACS (P = 0.004). Thus, for subjects with poorer motor performance, tACS with gamma oscillations applied over the M1 and contralateral cerebellar hemisphere improved their performance.

Association of Activities of Daily Living With Load During Step Ascent Motion in Nursing Home-Residing Elderly Individuals: An Observational Study.

OBJECTIVE: This study aimed to examine the association of independence in activities of daily living with the loads during step ascent motion and other motor functions in 32 nursing home-residing elderly individuals. DESIGN: Independence in activities of daily living was assessed by using the Functional Independence Measure. The loads at the upper (i.e., pulling up) and lower (i.e., pushing up) levels during the step ascent task was measured on a step ascent platform. Hip extensor, knee extensor, plantar flexor muscle, and quadriceps setting strengths; lower extremity agility using the stepping test; and hip and knee joint pain severities were measured. One-legged stance and functional reach distance for balance and maximal walking speed, timed up-and-go time, five-chair-stand time, and step ascent time were also measured to assess mobility. RESULTS: Stepwise regression analysis revealed that the load at pushing up during step ascent motion and timed up-and-go time were significant and independent determinants of Functional Independence Measure score. Functional Independence Measure score decreased with decreased load at pushing up and increased timed up-and-go time. CONCLUSIONS: The study results suggest that depending on task specificity, both one step up task's push-up peak load during step ascent motion and timed up-and-go can partially explain activities of daily living's Functional Independence Measure score in nursing home-residing elderly individuals. Lower extremity muscle strength, agility, pain, or balance measures did not add to the prediction.