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Dive into the research topics where Masaaki Nakajima is active.

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Featured researches published by Masaaki Nakajima.


Journal of Bodywork and Movement Therapies | 2013

Core exercises elevate trunk stability to facilitate skilled motor behavior of the upper extremities.

Yuki Miyake; Ryuji Kobayashi; Dolly Kelepecz; Masaaki Nakajima

OBJECTIVE The purpose of this study was to investigate the influence of core exercises on upper extremity function relative to skilled motor behavior and postural sway. METHOD We examined the effects of core exercises on the skilled motor behavior and postural sway of 40 healthy students who were assigned randomly to the core exercise group or the control group. Independent variable is extent of exposure to core exercise and dependent variables are skilled motor behavior and postural sway. A Purdue pegboard which measures skilled motor behavior and a stabilometer which measures postural sway were used to evaluate the influence of core exercises. Pre-intervention and post-intervention skilled motor behavior and postural sway were compared between the core exercise group and control group using the Wilcoxon rank sum test; a significance level of α = 0.05 was considered statistically significant. Also, we investigated the application of core exercises in a clinical setting for one patient with cerebral vascular disease. RESULTS The post intervention skilled motor behavior (p = 0.04) and postural sway, LNG (p = 0.05), LNG/TIME (p = 0.04) and X LNG (p = 0.02) were significantly higher in the core exercise group than control group. In the case report, there were good results; function of the upper extremity improved after doing the exercises. There were positive changes in some daily living activities. DISCUSSION Core exercises are likely to enhance trunk stabilization to improve upper extremity function. It is possible for core exercises to be adapted for patients.


Journal of Orthopaedic Research | 2003

Electromyographic analysis of a modified maneuver for quadriceps femoris muscle setting with co-contraction of the hamstrings.

Masaaki Nakajima; Kenji Kawamura; Isao Takeda

A „quadriceps femoris muscle setting”︁ is isometric quadriceps femoris exercise which can be widely used in early knee rehabilitation. However this exercise cannot obtain enough co‐contraction of the hamstrings. Isolated quadriceps femoris contraction in knee extension imposes severe strain to anterior cruciate ligament. We succeeded in developing a simple training maneuver that is effective in obtaining co‐contraction of the hamstrings—a modified maneuver for the quadriceps femoris muscle setting with the contralateral lower limb raised (MQS). In this study, we analyzed the effect of this maneuver by EMG quantification. Twenty‐eight healthy young adult men performed sequential trials consisting of normal quadriceps femoris muscle setting (NQS) and MQS. Electromyographic activity was recorded from surface electrodes on the gluteus maximus, vastus medialis, rectus femoris, vastus lateralis, semitendinosus and biceps femoris (long head), and normalized to values derived from maximal isometric trials. The % maximal voluntary isometric contraction (%MVIC) of the vastus medialis, vastus lateralis and rectus femoris did not vary in the each maneuver. However, the %MVIC of the hamstrings varied significantly in the MQS. This study suggests that effective co‐contraction of the hamstrings can be obtained in MQS by adjusting the load to the raised lower limb.


Evidence-based Complementary and Alternative Medicine | 2013

Static Magnetic Field Effects on Impaired Peripheral Vasomotion in Conscious Rats

Shenzhi Xu; Hideyuki Okano; Masaaki Nakajima; Naoya Hatano; Naohide Tomita; Yoshito Ikada

We investigated the SMF effects on hemodynamics in the caudal artery-ligated rat as an in vivo ischemia model using noninvasive near-infrared spectroscopy (NIRS) combined with power spectral analysis by fast Fourier transform. Male Wistar rats in the growth stage (10 weeks old) were randomly assigned into four groups: (i) intact and nonoperated cage control (n = 20); (ii) ligated alone (n = 20); (iii) ligated and implanted with a nonmagnetized rod (sham magnet; n = 22); and (vi) ligated and implanted with a magnetized rod (n = 22). After caudal artery ligation, a magnetized or unmagnetized rod (maximum magnetic flux density of 160 mT) was implanted transcortically into the middle diaphysis of the fifth caudal vertebra. During the experimental period of 7 weeks, NIRS measurements were performed in 3- , 5- , and 7-week sessions and the vasomotion amplitude and frequency were analyzed by fast Fourier transform. Exposure for 3–7 weeks to the SMF significantly contracted the increased vasomotion amplitude in the ischemic area. These results suggest that SMF may have a regulatory effect on rhythmic vasomotion in the ischemic area by smoothing the vasomotion amplitude in the early stage of the wound healing process.


Journal of Biomedical Materials Research Part B | 2016

Early tissue formation on whole-area osteochondral defect of rabbit patella by covering with fibroin sponge.

Eiichi Hirakata; Naohide Tomita; Yasushi Tamada; Toru Suguro; Masaaki Nakajima; Yusuke Kambe; Keisuke Yamada; Koji Yamamoto; Masahiro Kawakami; Akihisa Otaka; Hideo Okumura; Shigehiko Suzuki

Large osteochondral defects have been difficult to repair via tissue engineering treatments due to the lack of a sufficient number of source cells for repairing the defect and to the severe mechanical stresses affecting the replacement tissue. In the present study, whole-area osteochondral defects of rabbit patella were covered and wrapped with a fibroin sponge containing chondrocytes, with or without Green Fluorescent Protein (GFP) transgenic marking, on the surface facing the osteochondral defect. Five of eight osteochondral defects that were covered with the chondrocyte-seeded fibroin sponges showed hyaline cartilage-like repair containing no fibroin fragments at 6 weeks after surgery. The repaired tissue showed a layer formation, which showed intensive safranin-O and toluidine blue staining, and which showed positive type II collagen immunostaining. The average surface coverage of the repaired cartilage was 53%. On average, 48% of the cells in the repaired tissue were derived from GFP transgenic chondrocytes, which had been seeded in the fibroin sponge. The fibroin-sponge covering had the potential to allow the early repair of large osteochondral defects.


Journal of Bodywork and Movement Therapies | 2014

The effect of trunk coordination exercise on dynamic postural control using a Core Noodle.

Yuki Miyake; Shinichiro Nakamura; Masaaki Nakajima

OBJECTIVE To investigate the influence of trunk coordination exercise on dynamic postural control relative to postural sway. METHOD The effects of trunk coordination exercises were examined using a Core Noodle for the postural sway in healthy students who were assigned to an exercise or control group. The independent variable was the extent of exposure to Core Noodle exercise, and the dependent variable was dynamic postural control. A stabilometer, which measures dynamic postural control, was used to evaluate the effectiveness of the exercises. In addition, center of gravity movements were assessed using a Gravicorder G-620 stabilometer in which the subject was asked to shift their center of gravity between 2 circles on a computer monitor. Pre- and post-intervention dynamic postural control was statistically evaluated between the exercise group and control group using the Mann-Whitney test. Finally, we investigated the application of these exercises for a stroke patient. RESULTS AND CONCLUSION For post-intervention, the envelop area, mean length of the pathways between 2 circles, and the number of circles were significantly higher in the exercise group. Trunk coordination exercise performed Core Noodle may be used to enhance the dynamic postural balance of healthy young adults, and it can also be adapted for stroke patients.


Journal of Chiropractic Medicine | 2017

Clinical Validation of Pain Management Manipulative Therapy for Knee Osteoarthritis With the Squeeze-Hold Technique: A Case Series

Masaaki Nakajima

Objective: The purpose of this case series was to describe the short‐term and long‐term clinical effects of a manual technique for treating osteoarthritis (OA) knee pain. Methods: This study measured of the immediate effect and long‐term effect by using a case series of different groups of subjects. Knee OA and activity restriction in patients were evaluated by using the Kellgren‐Lawrence (K/L) Grading Scale and the Japanese Knee Osteoarthritis Measure (JKOM) index. In the intervention, lower limb muscles were squeezed by hand for 20 seconds. Each squeeze was performed for both lower limbs. Passive range‐of‐motion (ROM) exercise was performed on the knee joint. In one set of cases, immediate effects were measured after a one‐time treatment with pretreatment and posttreatment outcome measures. Eleven people with knee OA participated in the study. On a visual analogue scale (VAS) for pain, muscle stiffness, and muscular hemodynamics for estimation of muscle blood flow were recorded before and after the squeeze‐hold treatment. In another set of cases, the treatment was given to all patients once a week for 6 months, and long‐term effects were measured. Data on 5 subjects with knee OA were collected for 6 months after initial treatment. The VAS for pain and JKOM were recorded every month for 6 months. Results: For immediate effects, the VAS was 69 ± 21 mm before treatment and 26 ± 22 mm after treatment. Muscle stiffness was 8.8 ± 3.6 (absolute number) before treatment and 3.5 ± 2.1 after treatment. Tissue (muscle) oxygen saturation was 60.1 ± 5.7% before treatment and 65.3 ± 4.8% after treatment. Total hemoglobin was 24.3 ± 3.3 (absolute number) before treatment and 25 ± 2.3 after treatment. A tendency for reduction in OA knee pain and muscle stiffness was observed, and a tendency for increase was observed in the blood flow in the muscle. For long‐term effects in all 5 participants (any K/L grade, any JKOM score), OA knee pain and JKOM score improved gradually through 6 months. Conclusions: The participants in this case series showed improvement in pain and function. These findings indicate the feasibility of a larger study on the squeeze‐hold intervention for OA knee pain.


Journal of Bone and Joint Surgery-british Volume | 2016

TREATMENT FOR LOWER-LIMB MUSCLES BY SQUEEZE-HOLD TECHNIQUE IS VERY VALID FOR KNEE OA: ONE-YEAR FOLLOW-UP STUDY OF THREE CASES

Masaaki Nakajima; Aki Ota; Masanobu Murao; Masataka Nakadai; Makoto Egusa


Journal of Back and Musculoskeletal Rehabilitation | 2016

Magnitude of muscle activity of the lumbar multifidus using the Core-Noodle device with varied upper extremity postures

Masanobu Murao; Miki Tsuboi; Masaaki Nakajima


The Proceedings of Conference of Kansai Branch | 2005

815 Bio-environment Designing for Cartilage-regeneration Using Stem Cells

Yoshiyuki Kadobayashi; Koji Yamamoto; Hideo Yamamoto; Masaaki Nakajima; Shigeyuki Wakitani; Naohide Tomita


Proceedings of the JSME Bioengineering Conference and Seminar | 2005

222 幹細胞を用いた軟骨再生の環境設計(第2報)(OS1-07 : ティッシュ・エンジニアリング,マイクロ・ナノバイオメカニクス)

Koji Yamamoto; Tomohiro Terao; Yoshiyuki Kadobayashi; Masaaki Nakajima; Yasuji Harada; Shigeyuki Wakitani; Naohide Tomita

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Yasuji Harada

Nippon Veterinary and Life Science University

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Shigeyuki Wakitani

Mukogawa Women's University

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Masanobu Murao

Kibi International University

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Yuki Miyake

Kibi International University

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Aki Ota

Kibi International University

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