Yoshihiro Fukumoto

Effects of high-velocity resistance training on muscle function, muscle properties, and physical performance in individuals with hip osteoarthritis: a randomized controlled trial

Objective: To investigate the effects of high-velocity resistance training on muscle function, muscle properties, and physical performance in patients with hip osteoarthritis by comparison with those of low-velocity resistance training. Design: Single-blind randomized controlled trial. Setting: Home-based exercise programmes. Subjects: A total of 46 women with hip osteoarthritis were randomly assigned to the high-velocity (n = 23) or low-velocity (n = 23) training group. Interventions: Both groups underwent an eight-week daily home-based resistance training programme using an elastic band. Exercises involved hip abduction, extension, and flexion and knee extension. Participants in the high-velocity group performed the concentric phase of each repetition as rapidly as possible and returned to the initial position eccentrically in 3 s. Participants in the low-velocity group performed both the concentric and eccentric phases in 3 s. Main measures: The following outcome measures were evaluated: isometric muscle strength, muscle power, muscle thickness, muscle echo intensity, maximum walking speed, Timed Up and Go test, 3-minute walking test, Harris Hip Score, and hip pain. Results: Decreases in the time for performing the Timed Up and Go test (mean changes: high-velocity group −0.46 s, low-velocity group −0.23 s) and echo intensity of the gluteus maximus (mean changes: high-velocity group −6.8, low-velocity group −1.0) were significantly greater in the high-velocity group than in the low-velocity group. No significant difference was observed in changes of other outcome measures between the groups. Conclusion: This study revealed that high-velocity training for patients with hip osteoarthritis has partially a greater effect on muscle properties and physical performance than low-velocity training.

Association of sagittal spinal alignment with thickness and echo intensity of lumbar back muscles in middle-aged and elderly women

OBJECTIVEnQuantitative changes, such as a decrease in muscle mass, and qualitative changes, such as an increase in the amount of intramuscular non-contractile tissue, occur with aging. However, it is unclear whether quantitative or qualitative changes in back muscles are associated with spinal alignment in the standing position. We investigated the association of sagittal spinal alignment with muscle thickness as an index of the mass of lumbar back muscles and muscle echo intensity as an index of the amount of non-contractile tissue within these muscles.nnnMETHODSnStudy participants comprised 36 middle-aged and elderly women. Thickness and echo intensity of erector spinae, psoas major, and lumbar multifidus muscles were measured using an ultrasound imaging device. Standing sagittal spinal alignment, determined from thoracic kyphosis and lumbar lordosis angles, and the sacral anterior inclination angle was measured using the Spinal Mouse.nnnRESULTSnStepwise regression analysis performed using muscle thickness, echo intensity, and age as independent variables showed that erector spinae muscle thickness was a significant determinant of the thoracic kyphosis angle. Psoas major muscle thickness and echo intensity of the lumbar multifidus muscle were significant determinants of the sacral anterior inclination angle.nnnCONCLUSIONnOur results suggest that an increase in thoracic kyphosis is associated with a decrease in the mass of the erector spinae muscle, and that a decrease in pelvic anterior inclination is associated with a decrease in the mass of the psoas major muscle and an increase in the amount of non-contractile tissue within the lumbar multifidus muscle.

Pelvic instability and trunk and hip muscle recruitment patterns in patients with total hip arthroplasty.

Hip and lumbar spine disorders often coexist in patients with total hip arthroplasty (THA). The current study aimed to reveal pelvic motion pathology and altered trunk and hip muscle recruitment patterns relating to pelvic motion in patients with THA. Twenty-one women who underwent THA and 12 age-matched healthy women were recruited. Pelvic kinematics and muscle recruitment patterns (i.e., amplitude, activity balance, and onset timing) of the gluteus maximus, semitendinosus, multifidus, and erector spinae were collected during prone hip extension. Compared with healthy subjects, the patients showed increased pelvic motion, especially ventral rotation, decreased multifidus muscle activity relative to the hip extensors, and delayed onset of multifidus activity, despite reaction times and speeds of leg motion not being significantly different between the groups. Furthermore, while contributing factors associated with ventral pelvic rotation were not found, delayed onset of multifidus activity was detected as a factor related to the increased anterior tilt of the pelvis (r = 0.47, p < 0.05) in patients with THA. These results suggest that patients with THA have dysfunction of the stabilizer muscles of the lumbopelvic region along with increased pelvic motion.

Quantity and Quality of the Lower Extremity Muscles in Women with Knee Osteoarthritis

The objective of the study described here was to compare lower extremity muscle quantity and quality between individuals with and those without knee osteoarthritis (OA). Twenty-one women with knee OA (mild, n = 8; severe, n = 13) and 23 healthy patients participated. Ultrasonography was used to measure muscle thickness (MT) and echo intensity (EI) of the rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, biceps femoris, gluteus maximus, gluteus medius, gastrocnemius, soleus and tibialis anterior. MTs of the vastus medialis and vastus intermedius were smaller, and EIs of the vastus medialis, vastus intermedius, gluteus medius and tibialis anterior were larger, in the severe OA group compared than in the healthy group. Compared with the healthy group, the mild OA group had decreased MT and enhanced EI. Changes in quality and quantity occurring with knee OA progression differed among muscles. In the vastus medialis, change was observed from an earlier stage.

Compensatory turning strategies while walking in patients with hip osteoarthritis

The ability to change directions while walking is an integral component of adaptive locomotor behavior. Patients with hip osteoarthritis (OA) experience prolonged hip dysfunction. Gait compensation adopted by the patients with hip OA may become more pronounced while they turn. The purposes of this study were to identify the turning strategy while walking in patients with hip OA, and to examine the relationship between the turning strategy and the patients functional level. Fourteen patients with hip OA and 13 age-matched healthy controls were recruited. The hip, knee, and ankle joint angles and moments, and the foot progression angle were measured under three walking conditions (straight walking, 45° step turn, and 45° crossover turn), and the gait variables for each walking condition were compared between the 2 groups. The relationship between the increasing rate of knee and ankle joint moments in the turning to the straight walking and the functional point in the Harris hip score (HHS) was examined. The OA group showed decreased hip flexion, extension, and abduction angles, and hip flexion moment during the step turn, and decreased hip flexion, extension, and adduction angles, and hip abduction moment during the crossover turn. Furthermore, the ankle plantarflexion moment and the change in the foot angle during the stance phase were significantly increased during the crossover turn in the OA group. The increasing rate of the ankle plantarflexion moment correlated significantly with the functional point in the HHS. Patients with hip OA rely primarily on the ankle plantarflexors to compensate for the hip dysfunction while changing the walking direction.

Increase in echo intensity and extracellular-to-intracellular water ratio is independently associated with muscle weakness in elderly women

PurposeThe changes in muscle composition and its heterogeneity during aging are associated with muscle weakness in elderly persons independent of decreases in muscle mass or muscle thickness (MT). Both the assessment of echo intensity (EI) with ultrasound imaging and the evaluation of the extracellular water/intracellular water (ECW/ICW) ratio with segmental bioelectrical impedance spectroscopy (BIS) are non-invasive and convenient methods and seem valuable for muscle quality determination. However, no previous study has evaluated both EI and the ECW/ICW ratio simultaneously to investigate their relationship to muscle strength. The purpose of the present study was to investigate whether both EI and the ECW/ICW ratio are independently associated with muscle strength in elderly women.MethodsA total of 179 elderly women with a mean age of 74.1xa0±xa04.9xa0years, living independently in the community, were enrolled. The MT and EI of the quadriceps femoris were measured using transverse ultrasound imaging. The ECW/ICW ratio in the upper thigh was calculated from segmental BIS. The maximum knee extensor strength and the presence of knee pain were also assessed.ResultsKnee extensor strength showed a significant positive correlation with MT, and significant negative correlations with EI, the ECW/ICW ratio, and age. Stepwise regression analysis revealed that knee extensor strength in elderly women was predicted by MT, EI, and the ECW/ICW ratio.ConclusionsThis study suggests that the simultaneous application of EI and the ECW/ICW ratio is useful in assessing muscle strength, and accurately estimates the changes in muscle quality related to muscle weakness.

Factors associated with restricted hip extension during gait in women after total hip arthroplasty.

Purpose A decreased peak hip extension angle in the late stance phase is a major gait abnormality in patients with THA. The purpose of this study was to determine the relationship between peak hip extension angle during gait and functional impairments such as muscle weakness and the limitation in joint range of motion and to identify the clinical factors influencing peak hip extension angle during gait. Methods 67 female volunteers with THA were examined. Biomechanical gait analysis was performed to measure peak hip extension angle during gait. Maximal isometric strength of the hip and knee, passive hip extension range of motion, leg length discrepancy, and hip pain were assessed. Results Peak hip extension angle during gait significantly correlated with passive hip extension range of motion (r = 0.259), hip pain (r = −0.264), isometric strengths of the hip musculature (r = 0.278-0.491), and knee extensor (r = 0.386). Stepwise multiple regression analysis revealed that hip abductor torque (β = 0.355, P = 0.001), hip pain (β = −0.353, P = 0.001), and passive hip extension range of motion (β = 0.258, P = 0.011) were significant contributors to peak hip extension angle during gait (R2 = 0.408). Conclusions Our findings suggest that THA rehabilitation aimed at improving gait ability should focus on strengthening the hip abductors, controlling hip pain and increasing range of motion of hip extension.

Association of walking speed with sagittal spinal alignment, muscle thickness, and echo intensity of lumbar back muscles in middle-aged and elderly women

BackgroundAge-related change of spinal alignment in the standing position is known to be associated with decreases in walking speed, and alteration in muscle quantity (i.e., muscle mass) and muscle quality (i.e., increases in the amount of intramuscular non-contractile tissue) of lumbar back muscles. Additionally, the lumbar lordosis angle in the standing position is associated with walking speed, independent of lower-extremity muscle strength, in elderly individuals. However, it is unclear whether spinal alignment in the standing position is associated with walking speed in the elderly, independent of trunk muscle quantity and quality. The present study investigated the association of usual and maximum walking speed with age, sagittal spinal alignment in the standing position, muscle quantity measured as thickness, and quality measured as echo intensity of lumbar muscles in 35 middle-aged and elderly women.MethodsSagittal spinal alignment in the standing position (thoracic kyphosis, lumbar lordosis, and sacral anterior inclination angle) using a spinal mouse, and muscle thickness and echo intensity of the lumbar muscles (erector spinae, psoas major, and lumbar multifidus) using an ultrasound imaging device were also measured.ResultsStepwise regression analysis showed that only age was a significant determinant of usual walking speed. The thickness of the lumbar erector spinae muscle was a significant, independent determinant of maximal walking speed.ConclusionsThe results of this study suggest that a decrease in maximal walking speed is associated with the decrease in lumbar erector spinae muscles thickness rather than spinal alignment in the standing position in middle-aged and elderly women.

Associations of the step-up test and lower limb dysfunction: A post-hoc analysis of a prospective cohort study

BACKGROUNDnStep-up ability is considered to be associated with lower limb dysfunction. The objective of this research was to assess the height of the tallest step that could be mounted and to investigate its association with lower limb dysfunction.nnnMETHODSnWe previously conducted a two-year follow-up prospective cohort study. The study subjects were 119 patients receiving physiotherapy or exercise therapy at an orthopedic surgery clinic. The items evaluated were step-up ability (maximum step height), the timed up and go test, one-leg standing time and the 5-question Geriatric Locomotive Function Scale. The primary endpoint was the prevalence of locomotive syndrome, whereas secondary endpoint was musculoskeletal ambulation disability symptom complex (MADS). Evaluations were carried out at the time of the initial assessment and two years later. We used a multiple logistic regression model with age, sex, height, weight and each functional test as exploratory variables. R2 and C-statistics were calculated and these optimism biases were corrected using a bootstrap technique.nnnRESULTSnMaximum step height was strongly correlated with the prevalence of locomotive syndrome [odd ratio (95% confidence intervals), 0.52 (0.32, 0.87), pxa0=xa00.0074] and was correlated with MADS [0.45 (0.22, 0.92), pxa0=xa00.0138]. Additionally, maximum step height was also strongly correlated with post follow-up locomotive syndrome [0.39 (0.18, 0.84), pxa0=xa00.0010].nnnCONCLUSIONnThe results suggest that step-up ability may represent a simple and useful tool which is associated with lower limb dysfunction.

Muscle Thickness and Echo Intensity of the Abdominal and Lower Extremity Muscles in Stroke Survivors

Background and Purpose This study compared the muscle thickness (MT) and echo intensity (EI) of the abdominal, thigh, and lower leg muscles between the paretic and nonparetic sides in chronic stroke survivors. Methods Thirty-two stroke survivors living in the community participated in this study. The MT and EI, which are indicators of muscle mass and intramuscular fat or connective tissue, were assessed in the rectus abdominis, external oblique, internal oblique, transversus abdominis, rectus femoris, vastus intermedius, vastus lateralis, vastus medialis, tibialis anterior, gastrocnemius, and soleus via transverse ultrasound imaging. In addition, a possible indicator of physical activity—the frequency of going out per week—was evaluated. Results All quadriceps muscles and the tibialis anterior were significantly thinner and the EI values of the vastus intermedius, vastus lateralis, vastus medialis, and soleus were significantly higher in the paretic limb than the nonparetic limb. The MT and EI values of abdominal muscles did not differ significantly between the two sides. The MT values of the paretic rectus femoris, vastus lateralis, and vastus medialis were significantly associated with the frequency of going out after adjusting confounding factors. The MT of the nonparetic vastus lateralis was significantly associated with latency from stroke onset after adjusting confounding factors. Conclusions Our results indicate that quantitative and qualitative changes on the paretic side in stroke survivors were the most robust in the thigh muscles, whereas such changes might not occur in the abdominal muscles.