Noriaki Ichihashi

Evaluation of functional deficits determined by four different hop tests in patients with anterior cruciate ligament deficiency

Abstract The purpose of this study was to analyze the validity of the newly designed functional ability test (FAT) for the normal population and patients with deficiency of the anterior cruciate ligament (ACL). The FAT consists of four tests: the figure-of-eight hop, the up-down hop, the side hop, and the single hop. Sixty control subjects and 50 patients with unilateral ACL deficiency were tested. In the control group, the values measured were significantly different between males and females in all of the tests. On the other hand, when left/right difference values were compared, no significant difference was found between males and females in any of the tests. More than 95% of control group exhibited symmetrical function in each part of the FAT, whereas in the ACL-deficient group, the percentage of patients who showed abnormal symmetry was 68% in the figure-of-eight hop, 58% in the up-down hop, 44% in the side hop, and 42% in the single hop. The percentage of ACL-deficient patients with functional asymmetry in at least one of the four tests was 82%. The FAT was found to be useful in evaluating lower limb function in ACL-deficient patients.

Differences in muscle coactivation during postural control between healthy older and young adults

The purpose of this study was to clarify the difference in muscle coactivation during postural control between older and young adults and to identify the characteristics of postural control strategies in older adults by investigating the relationship between muscle coactivation and postural control ability. Forty-six healthy older adults (82.0±7.5 years) and 34 healthy young adults (22.1±2.3 years) participated. The postural tasks selected consisted of static standing, functional reach, functional stability boundary and gait. Coactivation of the ankle joint was recorded during each task via electromyography (EMG). The older adults showed significantly higher coactivation than the young adults during the tasks of standing, functional reach, functional stability boundary (forward), and gait (p<0.01). Postural sway area (ρ=0.42, p<0.05) and functional reach distance (ρ=-0.52, p<0.05) significantly correlated with coactivation during the corresponding task in older adults, i.e., muscle coactivation was significantly higher in the elderly with low postural control ability than in the elderly with high balance ability. Increased muscle coactivation could be a necessary change to compensate for a deterioration in postural control accompanying healthy aging. Further research is needed to clarify in greater detail positive and negative effects of muscle coactivation on postural control.

Acute and prolonged effect of static stretching on the passive stiffness of the human gastrocnemius muscle tendon unit in vivo

Static stretching (SS) is commonly used to prevent or improve limited joint mobility. However, it is unclear whether the components of the muscle‐tendon unit (MTU) are affected by 5 min of SS. This study investigated the acute and prolonged effect of SS on the mechanical properties of the MTU. The subjects comprised 15 male participants (mean age: 21.5 ± 1.6 years). MTU stiffness, muscle stiffness, tendon stiffness, and fascicle length of the gastrocnemius muscle were measured by ultrasonography and a dynamometer while the ankle was passively dorsiflexed. The measurements were performed prior to the 5 min of SS, immediately after the SS, and 10 min after the SS. MTU stiffness and muscle stiffness significantly decreased at both immediately and 10 min after SS, whereas no significant differences in MTU stiffness and muscle stiffness were found between immediately and 10 min after SS. Tendon stiffness immediately after SS was significantly higher than prior to and 10 min after SS. No significant change in the fascicle length occurred after SS. These results suggest that 5 min of SS affects MTU and muscle stiffness both immediately and 10 min after SS, which may be associated with a change in the connective tissue properties. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1759–1763, 2011

Fear of falling is associated with prolonged anticipatory postural adjustment during gait initiation under dual-task conditions in older adults

Little is known about dynamic balance control under dual-task conditions in older adults with fear of falling (FoF). The purpose of this study was to examine the effect of FoF on anticipatory postural adjustment (APA) during gait initiation under dual-task conditions in older adults. Fifty-seven elderly volunteers (age, 79.2 [6.8] years) from the community participated in this study. Each participant was categorised into either the Fear (n=24) or No-fear (n=33) group on the basis of the presence or absence of FoF. Under single- and dual-task conditions, centre of pressure (COP) data were collected while the participants performed gait initiation trials from a starting position on a force platform. We also performed a 10-m walking test (WT), a timed up & go test (TUG), and a functional reach test (FR). The reaction and APA phases were measured from the COP data. The results showed that under the dual-task condition, the Fear group had significantly longer APA phases than the No-fear group, although no significant differences were observed between the 2 groups in the reaction and APA phases under the single-task condition and in any clinical measurements (WT, TUG, and FR). Our findings suggest that specific deficits in balance control occur in subjects with FoF during gait initiation while dual tasking, even if their physical functions are comparable to subjects without FoF.

Age-related muscle atrophy in the lower extremities and daily physical activity in elderly women.

This study investigated the relationship between age-related declines in muscle thickness of the lower extremities and daily physical activity in elderly women. The subjects comprised 20 young women and 17 elderly women residing in a nursing home. Lower limb muscle thickness was measured by B-mode ultrasound with the following 10 muscles; gluteus maximus, gluteus medius, gluteus minimus, psoas major, rectus femoris, vastus lateralis, vastus intermedius, biceps femoris, gastrocnemius and soleus. Daily physical activity was evaluated using life-space assessment (LSA) which assessed the life-space level, degree of independence, and frequency of attainment. Muscle thickness in the gluteus maximus, gluteus medius, gluteus minimus, psoas major, rectus femoris, vastus lateralis, vastus intermedius, biceps femoris and gastrocnemius, but not soleus, was significantly greater in the young group than the elderly group. The greatest rates of age-related loss of skeletal muscle mass in the lower limbs showed in the psoas major, while the smallest loss showed in soleus muscle. Only the gluteus medius was significantly associated with the LSA score (r = 0.528, p < 0.05) in elderly women. These results suggest that the reduction in skeletal mass with age is smaller in soleus muscle, and that the age-related decline in gluteus medius muscle is influenced by daily physical activity.

DUAL-TASK WALK IS A RELIABLE PREDICTOR OF FALLS IN ROBUST ELDERLY ADULTS

National Institute on Aging (NIA). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIA or the National Institutes of Health. Dr. Markland received support through a Veterans Health Administration Career Development Award. Author Contributions: Alayne D. Markland: study concept and design, data analysis, interpretation of data, and manuscript preparation. Patricia S. Goode, Kathryn L. Burgio, and Holly E. Richter: study concept and design, interpretation of data, and critical review of the manuscript. David T. Redden: study concept and design, data analysis, interpretation of data, and critical review of the manuscript. Patricia S. Baker and Richard M. Allman: study concept and design, acquisition of subjects and data, interpretation of data, and critical review of the manuscript. Sponsor’s Role: The sponsors had no active role in the design, methods, subject recruitment, data collection, analysis, or manuscript preparation.

Relation between muscle thickness, spasticity, and activity limitations in children and adolescents with cerebral palsy

The aim of this study was to investigate the relation between muscle thickness of the quadriceps femoris muscle, knee joint function (spasticity and range of motion), and activity and participation measures in children and adolescents with cerebral palsy (CP). Thirty‐eight children and adolescents with mild to severe CP (20 males, 18 females; mean age 12y 8mo [SD 3y 7mo], range 6‐18y) participated. The severity and type of CP of participants covered all five levels of the Gross Motor Function Classification System and three types: spastic (quadriplegia, hemiplegia, and diplegia), athetotic, and hypotonic. The thickness of the quadriceps femoris muscle (MTQ) was measured from B‐mode ultrasound images. Activity limitations were evaluated by the Gross Motor Function Measurement‐66 (GMFM‐66) and the Pediatric Evaluation of Disability Inventory (PEDI). Spasticity was assessed with the modified Ashworth scale (MAS). After adjustment for age and body mass index, the MTQ showed significant positive correlations with GMFM‐66 and PEDI scores; however, there was no significant correlation with MAS ratings. The degree of knee flexion contracture correlated positively with the MAS rating of the knee flexor muscles and negatively with the MTQ. These results established the clinical relevance of assessment of muscle thickness across a broad spectrum of individuals with CP.

Acute effects of static stretching on muscle hardness of the medial gastrocnemius muscle belly in humans: an ultrasonic shear-wave elastography study.

This study investigated the acute effects of static stretching (SS) on shear elastic modulus as an index of muscle hardness and muscle stiffness and the relationship between change in shear elastic modulus and change in muscle stiffness after SS. The patients were 17 healthy young males. Muscle stiffness was measured during passive ankle dorsiflexion using a dynamometer and ultrasonography before (pre) and immediately after (post) 2 min of SS. In addition, shear elastic modulus was measured by a new ultrasound technique called ultrasonic shear wave elastography. The post-SS values for muscle stiffness and shear elastic modulus were significantly lower than the pre-SS values. In addition, Spearmans rank correlation coefficient indicated a significant correlation between rate of change in shear elastic modulus and rate of change in muscle stiffness. These results suggest that SS is an effective method for decreasing shear elastic modulus as well as muscle stiffness and that shear elastic modulus measurement using the shear wave elastography technique is useful in determining the effects of SS.

Atrophy of the lower limbs in elderly women: is it related to walking ability?

This study investigated the relationship between walking ability and age-related muscle atrophy of the lower limbs in elderly women. The subjects comprised 20 young women and 37 elderly women who resided in nursing homes or chronic care institutions. The elderly subjects were divided into three groups according to their walking ability. The muscle thickness of the following ten lower limb muscles were measured by B-mode ultrasound: the gluteus maximus, gluteus medius, gluteus minimus, psoas major, rectus femoris, vastus lateralis, vastus intermedius, biceps femoris, gastrocnemius and soleus. Compared to the young group, muscle thicknesses of all muscles except the soleus muscle were significantly smaller in all the elderly groups. There were no significant differences between the fast- and slow-walking groups in the thickness of any muscle. In the dependent elderly group, noticeable muscle atrophy was observed in the quadriceps femoris muscle. The results of this study suggest that the elderly who are capable of locomotion, regardless of their walking speed, show a moderate degree of age-related atrophy, while those who do not walk exhibit more severe atrophy, especially in the quadriceps femoris muscle.

Effects of calcaneal eversion on three-dimensional kinematics of the hip, pelvis and thorax in unilateral weight bearing

Understanding the kinematic chain from foot to thorax will provide a better basis for assessment of malalignment of the body. The purpose of this study was to investigate the effects of induced calcaneal eversion on the kinematics of the hip, pelvis and thorax in three dimensions under unilateral weight-bearing. Twenty-eight healthy males were requested to stand on one leg under three conditions: normal (standing directly on the floor), and on wedges producing 5° and 10° calcaneal eversion. Recorded kinematic parameters included the angles of the hip joint, pelvis, and thorax in three dimensions. Eversion induced by wedges produced significant increases in hip flexion, hip medial rotation, pelvic anterior tilt, and thoracic lateral tilt and axial rotation to the standing side. In the frontal plane, pelvic lateral tilt to the standing side was decreased in 5° eversion condition compared with normal condition; conversely, it was increased in 10° eversion condition compared with 5° eversion condition. Arch height was negatively correlated with change in thoracic axial rotation to standing side from the normal to 10° eversion (r=-.528, p<.01). We concluded that induced calcaneal eversion affects the three-dimensional kinematics of the thorax through the hip joint and the pelvis.