Takuya Sonoda

Reliability and Validity of Gait Analysis by Android-Based Smartphone

Smartphones are very common devices in daily life that have a built-in tri-axial accelerometer. Similar to previously developed accelerometers, smartphones can be used to assess gait patterns. However, few gait analyses have been performed using smartphones, and their reliability and validity have not been evaluated yet. The purpose of this study was to evaluate the reliability and validity of a smartphone accelerometer. Thirty healthy young adults participated in this study. They walked 20 m at their preferred speeds, and their trunk accelerations were measured using a smartphone and a tri-axial accelerometer that was secured over the L3 spinous process. We developed a gait analysis application and installed it in the smartphone to measure the acceleration. After signal processing, we calculated the gait parameters of each measurement terminal: peak frequency (PF), root mean square (RMS), autocorrelation peak (AC), and coefficient of variance (CV) of the acceleration peak intervals. Remarkable consistency was observed in the test-retest reliability of all the gait parameter results obtained by the smartphone (p<0.001). All the gait parameter results obtained by the smartphone showed statistically significant and considerable correlations with the same parameter results obtained by the tri-axial accelerometer (PF r=0.99, RMS r=0.89, AC r=0.85, CV r=0.82; p<0.01). Our study indicates that the smartphone with gait analysis application used in this study has the capacity to quantify gait parameters with a degree of accuracy that is comparable to that of the tri-axial accelerometer.

Community-Based Exercise Program is Cost-Effective by Preventing Care and Disability in Japanese Frail Older Adults

BACKGROUND In Japan, older adults are assessed by frailty checklist for care prevention. However, the effect of care prevention programs in community-dwelling frail older adults is still unclear. OBJECTIVES The purpose of this study was to investigate whether the care prevention program would reduce care and disability and to measure its cost-effectiveness in frail older adults. DESIGN This is a prospective study using propensity score matching. SETTING AND SUBJECTS A total of 610 community-dwelling older adults were recruited in 2 cities of Japan. INTERVENTION Subjects in the exercise group (n = 305) attended physical exercise sessions once a week for 16 consecutive weeks. The exercise sessions were in a standardized format consisting of moderate-intensity aerobic exercise, progressive strength training, flexibility and balance exercises, and cool-down activities. The control group (n = 305) received only screening evaluation. MEASUREMENTS Primary outcome was long term care insurance requirement certification during the 1-year follow-up period. Secondary outcome measurements were changes of frailty checklist, and care and medical cost. RESULTS Twenty-five subjects (8.1%) in the exercise group and 55 (18%) in the control group were newly certified for long-term care insurance service requirement in 1 year after the intervention (RR = 2.16, 95% CI = 1.46-3.20). Consequently, the health care cost for the subjects in the exercise group was significantly lower than in the control group (P < .001). Moreover, subjects in the exercise group had significant improvements in total scores of the frailty checklist compared with the control group that worsened after 1 year (exercise group: from 7.41 ± 3.98 to 7.11 ± 4.00, control group: from 7.34 ± 4.27 to 8.02 ± 4.81, F = 12.84, P < .001). CONCLUSION These results suggested that physical exercise is effective in preventing the progression of frailty and further disability in older adults living in the community. We could save heath care costs by our care prevention program.

Chronic kidney disease (CKD) is an independent risk factor for long-term care insurance (LTCI) need certification among older Japanese adults: A two-year prospective cohort study

CKD is associated with impairments in health status, physical function, and frailty. The aim of the current prospective cohort study was to determine whether CKD predicted new LTCI need certification among community-dwelling older Japanese adults. This was a prospective cohort study. We analyzed the cohort data from a prospective study, The Japan Multicenter Aging Cohort for Care Prevention (J-MACC). We followed 8063 elderly adults for 2 years, and we analyzed the relationship between CKD and LTCI need. The outcome studied was new certification for LTCI service need during a 2-year period. We measured serum creatinine (the estimated glomerular filtration rate; eGFR), serum albumin, frailty checklist scores, and body mass index. During the 2-year follow-up, 536 subjects (6.6%) were newly certified as needing LTCI services. We stratified the cohort according to eGFR quartile and performed multivariate analyses using an eGFR value of 71.4-83.6 ml/min/1.73 m(2) as a reference. We found that subjects with eGFR values <60.0 ml/min/1.73 m(2) had a significantly elevated risk of LTCI service need (adjusted hazard ratio: 1.44 [95% CI 1.12-1.86]). Our results indicate that CKD is independently associated with new LTCI service need certification and is an important marker of frailty in older adults.

Cognitive decline predicts long-term care insurance requirement certification in community-dwelling older Japanese adults: a prospective cohort study.

Aim: The purpose of this prospective cohort study is to examine whether cognitive decline is an independent predictor of new long-term care insurance (LTCI) requirement certifications in Japan. Methods: A total of 5,765 community-dwelling older Japanese adults who, at baseline, were independent in terms of their activities of daily living participated in this study and were followed up for 18 months. The outcome measure was the number of new LTCI requirement certifications during the 18-month period of the study. We collected demographic information through questionnaires and assessed cognitive skills with the Cognitive Performance Scale (CPS). The participants were divided into 3 groups according to CPS scores (0, 1, and 2 or greater). Results: During the 18-month period, 399 subjects (6.9%) became newly certified for LTCI services. In a multivariate Cox proportional hazards model, older participants with a CPS score of 1 (adjusted HR: 1.39, 95% CI: 1.08-1.77) and 2 or greater (adjusted HR: 2.27, 95% CI: 1.74-2.96) were significantly more likely to receive an LTCI certification compared to those with a CPS score of 0. Conclusions: Cognitive decline is an independent predictor of new LTCI requirement certifications and the severity of cognitive decline in elderly adults is positively associated with receiving an LTCI requirement certification in Japan.

Effect of Capacitive and Resistive Electric Transfer on Tissue Temperature,Muscle Flexibility, and Blood Circulation

Introduction: The differences between Capacitive and Resistive electric transfer (CRet) and hot pack (HP) in their effects on tissue temperature, muscle flexibility, and blood circulation are unknown. This study aimed to clarify the effect of CRet and HP on tissue temperature, muscle flexibility, and blood circulation. Methods: The participants were 13 healthy adults. They randomly performed three 15-minute interventions: (1) CRet, (2) HP, and (3) without powered CRet (sham). The intervention and measurement were applied to the right hamstring muscle. INDIBA® activ ProRecovery HCR902 was used in the CRet trial. The moist heat method was used in the HP trial. The measurement indexes were superficial temperature (ST), 10-mm deep temperature (DT), and 20-mm DT; the passive straight leg raise (SLR) test; and oxygenated (oxy), deoxygenated (deoxy), and total (total) hemoglobin (Hb) concentrations. Each index was measured for 30 minutes after the intervention and the amount of change (Δ) from the pre-intervention value was calculated. Results: ΔST, Δ10 mmDT, Δ20 mmDT, Δoxy-Hb, and Δtotal-Hb were significantly higher in the CRet and HP trials than in the sham trial for 30 minutes after the intervention (p<0.05). ΔSLR was significantly higher in the CRet trial than in the HP trial from 15 to 30 minutes after the intervention (p<0.01) Conclusion: Our results indicate that CRet is an efficient method for preventing and treating musculoskeletal injuries and improve muscle flexibility. In addition, it can improve blood circulation as well as HP can.

Effect of Capacitive and Resistive electric transfer on haemoglobin saturation and tissue temperature

Abstract Purpose: This study aims to evaluate the effects of Capacitive and Resistive electric transfer (CRet) and hotpack (HP) on haemoglobin saturation and tissue temperature. Materials and methods: The participants were 13 healthy males (mean age 24.5 ± 3.0). They underwent three interventions on different days: (1) CRet (CRet group), (2) HP (HP group) and (3) CRet without power (sham group). The intervention and measurement were applied at the lower paraspinal muscle. Indiba® active ProRecovery HCR902 was used in the CRet group, and the moist heat method was used in the HP group. Oxygenated, deoxygenated and total haemoglobin (oxy-Hb, deoxy-Hb, total-Hb) counts were measured before and after the 15-min interventions, together with the temperature at the skin surface, and at depths of 10 mm and 20 mm (ST, 10mmDT and 20mmDT, respectively). The haemoglobin saturation and tissue temperature were measured until 30 min after the intervention and were collected at 5-min intervals. Statistical analysis was performed for each index by using the Mann–Whitney U test for comparisons between all groups at each time point. Results: Total-Hb and oxy-Hb were significantly higher in the CRet group than in the HP group continuously for 30 min after the intervention. The 10mmDT and 20mmDT were significantly higher in the CRet group than in the HP group from 10- to 30 min after intervention. Conclusions: The effect on haemoglobin saturation was higher in the CRet group than in the HP group. In addition, the CRet intervention warmed deep tissue more effectively than HP intervention.

Effect of Capacitive and Resistive electric transfer on changes in muscle flexibility and lumbopelvic alignment after fatiguing exercise

[Purpose] This study aimed to clarify the effects of Capacitive and Resistive electric transfer (CRet) on changes in muscle flexibility and lumbopelvic alignment after fatiguing exercise. [Subjects and Methods] Twenty-two healthy males were assigned into either the CRet (n=11) or control (n=11) group. Fatiguing exercise and CRet intervention were applied at the quadriceps muscle of the participants’ dominant legs. The Ely test, pelvic tilt, lumbar lordosis, and superficial temperature were measured before and after exercise and for 30 minutes after intervention. Statistical analysis was performed using one-way analysis of variance, with Tukey’s post-hoc multiple comparison test to clarify within-group changes and Student’s t-test to clarify between-group differences. [Results] The Ely test and pelvic tilt were significantly different in both groups after exercise, but there was no difference in the CRet group after intervention. Superficial temperature significantly increased in the CRet group for 30 minutes after intervention, in contrast to after the exercise and intervention in the control group. There was no significant between-group difference at any timepoint, except in superficial temperature. [Conclusion] CRet could effectively improve muscle flexibility and lumbopelvic alignment after fatiguing exercise.

Forefoot transverse arch height asymmetry is associated with foot injuries in athletes participating in college track events

[Purpose] The association between foot injuries and foot alignment, including the transverse arch height (TAH) and asymmetry, was examined in athletes participating in college track events. [Participants and Methods] This study included 55 male athletes participating in a college track and field club. Data including demographic information and the incidence of foot injuries within a year prior to participation in this study were obtained via questionnaires. TAH and the medial longitudinal arch height during 10 and 90% loading, leg-heel alignment, and the heel angle were measured before calculating the asymmetry of each alignment parameter measured. Participants were categorized into an injury or a normal group. Unpaired t-tests were used to perform between-group comparisons for each alignment parameter measured and asymmetry. Additionally, logistic regression analysis was performed to identify factors associated with foot injuries after adjustment for demographic data. [Results] TAH asymmetry during 10 and 90% loading was significantly greater in the injury group. Further logistic regression analysis performed showed that only TAH asymmetry during 90% loading was significantly associated with foot injuries after adjustment for demographic data. [Conclusion] With regard to track events, a greater asymmetry of forefoot TAH in a weight-bearing position was observed to be associated with foot injuries.

Relationship between agility and lower limb muscle strength, targeting university badminton players

[Purpose] Targeting university badminton players, this study investigated the relationship between agility, which is associated with performance in badminton, and lower limb muscle strength, and examined which muscles influence agility. [Subjects and Methods] A total of 23 male university badminton players were evaluated for side-shuffle test scores and lower limb strength. The relationships between agility, lower limb strength, and duration of experience playing badminton were evaluated using a correlation analysis. Moreover, the relationship between agility and lower limb strength was evaluated by partial correlation analysis, adjusting for the effects of experience of each badminton player. [Results] The agility score correlated with hip extension and ankle plantar flexion strength, with adjustment for badminton experience. [Conclusion] This study suggests that hip extension training and improvement in ankle plantar flexion strength may improve agility.

Relationship between transverse arch height and foot muscles evaluated by ultrasound imaging device

[Purpose] Few studies on the transverse arch (TA) in the forefoot have been conducted. The forefoot is where pains occur most frequently and is related to walking and balance; hence, paying attention to TA is vital. However, the relationship between TA and foot muscles has not been investigated. Therefore, this study aims to investigate muscles related to TA. [Subjects and Methods] Nineteen healthy young males were included. Measurements of their feet, excluding one foot with recent foot pain (n=37), were obtained. The height of TA (TAH) was measured in two ways: during 10% and 90% loading of body weight. The cross-sectional area and thickness of five muscles were measured: flexor digitorum longus, peroneus longus and brevis, flexor hallucis brevis, flexor digitorum brevis (FDB) and abductor hallucis (ABH). All measurements were performed with an ultrasound device. [Results] FDB and ABH were correlated with TAH during 10% and 90% loading after removing the effect of body mass index and age. The greater FDB and ABH, the higher TAH. [Conclusion] As FDB becomes larger, the second, third and fourth metatarsal heads are raised more. Furthermore, the height of the first metatarsal head is lowered by a larger ABH. These mechanisms may increase TAH.