Suguru Torii

Niigata University of Health and Welfare, Niahi-niigata, Niigata, Japan

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Publications (14)20.37 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Osteoarthritis patients may exhibit different kinematics according to the disease stage. However, changes in the frontal and horizontal planes in each stage remain unclear. The purpose of this study was to investigate changes in the knee kinematic gait variables of osteoarthritis patients, including the frontal and horizontal planes, with respect to the severity of the disease. Forty-five patients with knee osteoarthritis and 13 healthy young subjects were recruited for the experiment. All subjects were examined while walking on a 10-m walkway at a self-selected speed. In each trial, we calculated the angular displacements of flexion/extension, abduction/adduction, and external/internal tibial rotation. We also measured muscle strength, range of motion (ROM), and alignment. We compared the differences in osteoarthritis severity and knee kinematic variables between osteoarthritis patients and normal subjects. The flexion angle at the time of foot contact was significantly less in patients with severe and moderate osteoarthritis than in normal subjects (both p<0.01). The abduction angle at the 50% stance phase was significantly less in patients with severe osteoarthritis than in normal subjects (p<0.05). The excursion of axial tibial rotation was significantly less in patients with early osteoarthritis than in normal subjects (p<0.05). Osteoarthritis patients had different knee kinematics during gait, depending on the progress of osteoarthritis. Early-stage patients exhibit decreased axial tibial rotation excursion, while severe-stage patient exhibit increased knee adduction.
    The Knee 12/2011; 19(5):628-32. · 2.01 Impact Factor
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    ABSTRACT: We examined muscle-specific ubiquitin ligases MAFbx/Atrogin-1 and MuRF1 gene expression resulting from immobilization-induced skeletal muscle atrophy of slow-twitch soleus and fast-twitch plantaris muscles. Male C57BL/6 mice were subjected to hindlimb immobilization, which induced similar percentage decreases in muscle mass in the soleus and plantaris muscles. Expression of MAFbx/Atrogin-1 and MuRF1 was significantly greater in the plantaris muscle than in the soleus muscle during the early stage of atrophy. After a 3-day period of atrophy, total FOXO3a protein level had increased in both muscles, while phosphorylated FOXO3a protein had decreased in the plantaris muscle, but not in the soleus muscle. PGC-1α protein expression did not change following immobilization in both muscles, but basal PGC-1α protein in the soleus was markedly higher than that in plantaris muscles. These data suggest that although soleus and plantaris muscles atrophied to a similar extent and that muscle-specific ubiquitin protein ligases (E3) may contribute more to the atrophy of fast-twitch muscle than to that of slow-twitch muscle during immobilization.
    The Journal of Physiological Sciences 09/2011; 61(6):537-46. · 1.09 Impact Factor
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    ABSTRACT: The present study was performed to develop regression-based prediction equations for fat mass by ultrasound in Japanese children and to investigate the validity of these equations. A total of 127 healthy Japanese pre-pubertal children aged 6-12 years were randomly separated into two groups: the model development group (fifty-four boys and forty-four girls) and the validation group (eighteen boys and eleven girls). Total body, trunk, arm and leg fat masses were initially determined by dual-energy X-ray absorptiometry (DXA, Delphi A-QDR whole-body scanner; Hologic, Inc., Bedford, MA, USA). Then, fat thickness was measured by B-mode ultrasound (5 MHz scanning head) at nine sites (arm: lateral forearm, anterior and posterior upper arm; trunk: abdomen and subscapular; leg: anterior and posterior thigh, anterior and posterior lower leg). Regression analyses were used to describe the relationships between the site-matched fat masses (total body, arm, trunk and leg) obtained by DXA and ultrasound in the development group. When these fat mass prediction equations were applied to the validation group, the measured total and regional fat mass was very similar to the predicted fat mass (mean difference calculated as predicted - measured fat mass ± 2 SD; total body 0·1 (SD 0·5) kg, arm 0·1 (SD 0·3) kg, trunk - 0·1 (SD 0·3) kg, leg 0·1 (SD 0·5) kg for boys; total body 0·5 (SD 1·3) kg, arm 0·0 (SD 0·3) kg, trunk 0·1 (SD 0·8) kg, leg 0·3 (SD 0·6) kg for girls), and the Bland-Altman analysis did not indicate a bias. These results suggest that ultrasound-derived prediction equations for boys and girls are useful for estimating total and regional fat mass.
    The British journal of nutrition 05/2011; 106(6):944-50. · 3.45 Impact Factor
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    ABSTRACT: The present study was performed to develop regression based prediction equations for fat mass from skinfold thickness in Japanese children, and to investigate the cross-sectional and longitudinal validity of these equations. A total of 127 healthy Japanese prepubertal children aged 6-12 years were randomly separated into two groups: the model development group (54 boys and 44 girls) and the cross-sectional validation group (18 boys and 11 girls). Fat mass was initially determined by using DXA (Hologic Delphi A-QDR whole-body scanner) to provide reference data. Then, fat thickness was measured at triceps and subscapular using an Eiken-type skinfold calipers. Multiple anthropometric and DXA measures were obtained one year later for 28 of the original 127 subjects (longitudinal validation group: 14 boys and 14 girls). Strong significant correlations were observed between total fat mass by DXA measurement and the skinfold thickness × height measures by caliper in the model development group of boys and girls (R2=0.91-0.92, p<0.01). When these fat mass prediction equations were applied to the cross-sectional and longitudinal validation groups, the measured total fat mass was also very similar to the predicted fat mass. In addition, there were significant correlations between the measured and predicted total fat mass for boys and girls, respectively, although Bland-Altman analysis indicated a bias in cross-sectional validation group. Skinfold-derived prediction equations underestimate for obese children but are generally useful for estimating total fat mass in field research.
    Asia Pacific Journal of Clinical Nutrition 01/2011; 20(3):426-31. · 1.06 Impact Factor
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    ABSTRACT: The purpose of this study was to investigate the effect of intensive eccentric exercise on hamstring muscles by using magnetic resonance imaging (MRI) and to elucidate the relationships between the changes in the electromyographic (EMG) parameters and in the transverse relaxation time (T2) of the hamstring muscles. Seven male volunteers performed eccentric knee flexion exercise, and the EMG activity of the hamstring muscles was simultaneously measured. Before and immediately after the exercise, the maximum isometric knee flexion torque was measured and MR images of the hamstring muscles were obtained. For all hamstring muscles, the EMG activity of the fifth set was significantly lower than that of the first set. For each subject, a significant correlation was detected between the percentage change in the value of the post-exercise T2 value and those of EMG signals during the exercise only for the semitendinosus (ST) muscle and not for the biceps femoris (BF) and the semimembranosus (SM) muscles. These results suggested that the EMG-activity reductions in the BF, ST, and SM muscles were due to neuromuscular fatigue, and moreover the reduction in the ST muscle was due to a failure in the E-C coupling, which was caused by excessive muscle-fiber damage.
    International Journal of Sports Medicine 04/2009; 30(7):533-7. · 2.27 Impact Factor
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    ABSTRACT: The semitendinosus (ST) muscle has a tendinous intersection within the muscle belly that separates the ST muscle into distinct proximal and distal compartments. Thus far, no study has compared the electromyographic (EMG) activities between the proximal and distal compartments of the human ST muscle. This study aimed to investigate the intramuscular EMG activity patterns of the proximal and distal compartments of the ST muscle by altering the hip and knee joint positions. The study population comprised eight healthy male volunteers. They performed ramp isometric knee flexion tasks form the relaxed state to the maximal voluntary contraction (MVC) state with (1) the hip and knee at 90 degrees and 0 degrees, respectively (90-0 position), (2) both the hip and knee at 00 (0-0 position), and (3) the hip and knee at 0 degrees and 90 degrees, respectively (0-90 position). Fine-wire electrodes were inserted into the proximal and distal compartments of the ST muscle and the individual EMG activities were recorded. In the 90-0 position, the EMG activity of the distal compartment was higher than that of the proximal compartment at 60%, 80%, and 90% MVC. Moreover, in the 0-90 position, the EMG activity of the proximal compartment was higher than that of the distal compartment at 60% MVC. These results indicated that the lengthened or shortened muscle conditions induced regional differences in the EMG activity patterns, while the two compartments showed equivalent activity when the muscle length was moderate.
    Electromyography and clinical neurophysiology 01/2009; 49(4):149-54.
  • Medicine and Science in Sports and Exercise - MED SCI SPORT EXERCISE. 01/2009; 41.
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    ABSTRACT: This study was designed to determine the regional differences of magnetic resonance (MR) measurements in the hamstrings [biceps femoris muscle long head (BFl) and short head (BFs), semimembranosus muscle (SM), and semitendinosus muscle (ST)] following eccentric knee-flexion exercise. Twelve male volunteers performed eccentric knee-flexion exercise. Maximum isometric torque, plasma creatine kinase (CK) activity, muscle soreness, and MR images of the hamstrings were measured before and immediately following exercise, and on the first, second, third and seventh days following the exercise. Cross-sectional areas (CSAs) and transverse relaxation times (T2s) of the hamstrings were measured from the T2-weightened MR imaging sequences of 30% (proximal), 50% (middle), and 70% (distal) areas of the thigh length. The CSA of the ST at proximal and middle regions had significantly increased on the third day, but no significant changes were found for the BFl or SM. Immediately following exercise, T2 values had increased significantly in the BFs, BFl, and ST. On the third day, T2 values of only ST increased significantly at proximal, middle and distal regions. Significant differences of T2 values between proximal and distal regions in the ST were found for the second, third and seventh days following the exercise. These results suggest that because of the anatomical characteristics of the muscles, the degrees of response following the exercise differed among the muscles and the regions of ST muscle.
    Arbeitsphysiologie 01/2008; 101(6):713-20. · 2.66 Impact Factor
  • Medicine and Science in Sports and Exercise - MED SCI SPORT EXERCISE. 01/2008; 40.
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    ABSTRACT: To determine--with the assistance of a larger sample size--whether the inconsistency of reducing the knee-joint varus moment with a lateral wedge in patients with medial compartment knee osteoarthritis (OA) persists and if so, what underlying mechanisms may explain it. Crossover design whereby 51 patients with bilateral isolated medial compartment knee OA and 19 age-matched healthy controls walked with two different wedge conditions: a 0-degree control wedge and a 6-degree lateral wedge. We conducted three-dimensional motion analysis, hip-knee-ankle (HKA) angle measurement, and radiologic assessment with Kellgren-Lawrence grade. We investigated frontal plane angles and moments at the knee and subtalar joints, ground reaction forces, and center of pressure (CoP). Moments were derived using a three-dimensional inverse dynamics model of the lower extremity. Nine patients (17.6%) had an increased knee-joint varus moment with the 6-degree lateral wedge via the medially shifted location of the CoP. These patients did not differ from the remaining patients in HKA angle and radiologic assessment. In approximately 18% of patients with bilateral medial compartment knee OA, the 6-degree lateral wedge seems to fail to reduce the knee-joint varus moment. The indication and limitations of lateral wedge should be confirmed by a randomized controlled study.
    American Journal of Physical Medicine & Rehabilitation 07/2007; 86(6):446-54. · 1.73 Impact Factor
  • Medicine and Science in Sports and Exercise - MED SCI SPORT EXERCISE. 01/2007; 39.
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    ABSTRACT: This study assessed the biomechanic effects of wearing a lateral wedge on the subtalar joint moment during gait in athletes with and without an unstable lateral ankle. A crossover design was applied whereby 50 collegiate males walked with two different wedges: a 0 degrees control wedge and a 6 degrees lateral wedge. We investigated frontal plane angles and moments at the subtalar joint and the knee joint, as well as ground reaction forces and center of pressure excursion. Moments were derived using a three-dimensional inverse dynamics model of the lower extremity. The 6 degrees lateral wedge significantly increased the subtalar joint valgus moment (P < 0.001) and reduced the knee joint varus moment (P < 0.001) when compared with no wedge. The differences between wedge conditions were associated with a laterally shifted location of the center of pressure during stance phase. However, there were diverse, sometimes reversed effects with the wedge among the athletes with an unstable lateral ankle. These results indicate that biomechanical indications and limitations of lateral wedges in unstable lateral ankles should be analyzed in more detail, possibly leading to new guidelines for the use of such foot orthoses.
    American Journal of Physical Medicine & Rehabilitation 12/2005; 84(11):858-64. · 1.73 Impact Factor
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    ABSTRACT: To assess the biomechanic effects of wearing a lateral wedge on the knee joint varus moment during gait in elders with and without knee osteoarthritis (OA). Crossover design whereby subjects walked under 2 different insole conditions: a 0 degrees control wedge and a 6 degrees lateral wedge. A gait laboratory with 3-dimensional motion analysis and force platform equipment. Thirteen healthy subjects and 13 knee patients with OA. Not applicable. Frontal plane angles and moments at the knee and subtalar joints, ground reaction forces, and center of pressure. Moments were derived by using a 3-dimensional inverse dynamics model of the lower extremity. The 6 degrees lateral wedge significantly reduced knee joint varus moment and increased subtalar joint valgus moment in both groups when compared with no wedge. All patients had a greater knee joint varus moment with a similar subtalar joint valgus moment compared with the people without OA. There were diverse, sometimes reversed effects with the insole among the patients. The 6 degrees lateral wedge did not consistently reduce the knee joint varus moment in patients with knee OA. The biomechanic indications and limitations of laterally wedged insoles should be confirmed by a larger study.
    Archives of Physical Medicine and Rehabilitation 08/2005; 86(7):1465-71. · 2.36 Impact Factor
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    ABSTRACT: The aim of this study was to test whether anticipation of upcoming head blow stimuli, which elicit reflex responses in the neck muscle, makes the reflex responses greater or not. In nine healthy subjects the reflex responses were elicited in the sternocleidomastoid (SCM) muscle in the eyes-open (EO) and eyes-closed (EC) conditions, which corresponded to the predictable and unpredictable conditions, respectively. The subjects were instructed not to resist the perturbations after the impact. The results demonstrated that the reflex response of the SCM muscle was significantly smaller in the predictable EO condition than in the unpredictable EC condition (P < 0.05), although no significant differences were observed in either the background EMG activities or the head accelerations. Further, this effect of anticipation was observed only in the later reflex EMG component, which most probably mediated the stretch reflex pathway. In contrast, no significant difference was observed in the early component, which was presumed to be the vestibular-collic reflex. The reduced stretch reflex response was suggested to be functionally relevant to the task requirement, i.e., to let the neck extension movement occur, and not to resist after the impact of the head blow. It was concluded that the anticipation has an effect on reducing the stretch reflex responses in the neck muscle, but does not have any effect on the presumed vestibular-collic reflex under the present experimental paradigm. It is suggested that the gain of the stretch reflex pathway is modulated by anticipatory information of upcoming mechanical event.
    Neuroscience Letters 08/2004; 366(2):206-10. · 2.03 Impact Factor

Publication Stats

133 Citations
20.37 Total Impact Points

Institutions

  • 2011
    • Niigata University of Health and Welfare
      Niahi-niigata, Niigata, Japan
  • 2005–2011
    • Waseda University
      • • Faculty of Sport Sciences
      • • Graduate School of Human Sciences
      Edo, Tōkyō, Japan
  • 2007
    • National Rehabilitation Center for Persons with Disabilities
      Tokorozawa, Saitama, Japan