山子 剛 (ヤマコ ゴウ)

YAMAKO Go

写真a

職名

准教授

研究分野・キーワード

生体機械工学

取得学位 【 表示 / 非表示

  • 新潟大学 -  博士(工学)

専門分野(科研費分類) 【 表示 / 非表示

  • 生体医工学・生体材料学

  • 機械材料・材料力学

 

論文 【 表示 / 非表示

  • Effects of a valgus unloader brace in the medial meniscectomized knee joint: a biomechanical study.

    Shriram D, Yamako G, Chosa E, Lee YHD, Subburaj K

    Journal of orthopaedic surgery and research   14 ( 1 ) 44   2019年02月  [査読有り]

    共著

    DOI PubMed

  • Acetabular reinforcement ring with additional hook improves stability in three-dimensional finite element analyses of dysplastic hip arthroplasty

    Totoribe K., Chosa E., Yamako G., Zhao X., Ouchi K., Hamada H., Deng G.

    Journal of Orthopaedic Surgery and Research   13 ( 1 ) 313   2018年12月  [査読有り]

    共著

     概要を見る

    © 2018 The Author(s). Background: The stability of acetabulum reconstructions using reinforcement rings and hooks is important for successful replacement surgery. The objective of this study was to biomechanically determine the effects of the hook on stress and the related micromotions of the acetabular reinforcement ring during the immediate postoperative period. Methods: Acetabular reinforcement ring models were developed using a nonlinear, three-dimensional, finite element method. Using a pre-prepared template, we constructed without-hook and bone graft models of varying volumes and material properties. Results: The stress on the inferior margin of the acetabulum was higher in the with-hook model than in the without-hook model, especially with increased bone graft volumes, and the stiffness of the bone graft material was decreased. Relative micromotions in the without-hook model were higher than in the with-hook models. The highest relative micromotion was observed in the model with increased bone graft volume and lower stiffness of bone graft material. Conclusions: In biomechanical analyses, the hook effectively dispersed stress and improved the initial fixation strength of the acetabular reinforcement ring.

    DOI PubMed

  • Biomechanical analysis of supra-acetabular insufficiency fracture using finite element analysis

    Tanaka H., Yamako G., Kurishima H., Yamashita S., Mori Y., Chiba D., Chosa E., Itoi E.

    Journal of Orthopaedic Science   23 ( 5 ) 825 - 833   2018年09月  [査読有り]

    共著

     概要を見る

    © 2018 Background: Supra-acetabular insufficiency fractures (SAIFs) occur in the upper acetabulum and are rare compared with insufficiency sacral, femoral head, or ischial fractures. However, SAIFs are known to occur in low grade trauma, and the underlying mechanism is still remained unclear. Methods: We performed biomechanical analysis using finite element analysis to clarify the mechanisms underlying the development of SAIFs. Patient-specific models and bone mineral density (BMD) were derived from pelvic computed tomography data from two patients with SAIF (unaffected side) and two healthy young adults. The bone was assumed to be an isotropic, linearly elastic body. We assigned Young's modulus of each element to the pelvis based on the BMD, and reported the relationships for BMD–modulus. Clinically relevant loading conditions—walking and climbing stairs—were applied to the models. We compared the region of failure risk in each acetabulum using a maximum principal strain criterion. Results: The average supra-acetabular BMD was less than that of the hemi-pelvis and femoral head, but was higher than that of the femoral neck and greater trochanter. Greater minimum principal strain was concentrated in the supra-acetabular portion in both the SAIF and healthy models. In the SAIF models, the higher region of the failure risk matched the fracture site on the acetabulum. Conclusions: Relative fragility causes compressive strain to concentrate in the upper acetabulum when walking and climbing stairs. When presented with a patient complaining of hip pain without apparent trauma or abnormal X-ray findings, physicians should consider the possibility of SAIF and perform magnetic resonance imaging for the diagnosis of SAIF.

    DOI

  • Finite element analysis of the tibial bone graft in cementless total knee arthroplasty

    Totoribe K., Chosa E., Yamako G., Hamada H., Ouchi K., Yamashita S., Deng G.

    Journal of Orthopaedic Surgery and Research   13 ( 1 ) 113   2018年05月  [査読有り]

    共著

     概要を見る

    © 2018 The Author(s). Background: Achieving stability of the tibial implant is essential following cementless total knee arthroplasty with bone grafting. We investigated the effects of bone grafting on the relative micromotion of the tibial implant and stress between the tibial implant and adjacent bone in the immediate postoperative period. Methods: Tibial implant models were developed using a nonlinear, three-dimensional, finite element method. On the basis of a preprepared template, several bone graft models of varying sizes and material properties were prepared. Results: Micromotion was larger in the bone graft models than in the intact model. Maximum micromotion and excessive stress in the area adjacent to the bone graft were observed for the soft and large graft models. With hard bone grafting, increased load transfer and decreased micromotion were observed. Conclusions: Avoidance of large soft bone grafts and use of hard bone grafting effectively reduced micromotion and undue stress in the adjacent area.

    DOI PubMed

  • Quantification of the sit-to-stand movement for monitoring age-related motor deterioration using the Nintendo Wii Balance Board

    Yamako G., Chosa E., Totoribe K., Fukao Y., Deng G.

    PLoS ONE   12 ( 11 )   2017年11月

    共著

     概要を見る

    © 2017 Yamako et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Simple methods for quantitative evaluations of individual motor performance are crucial for the early detection of motor deterioration. Sit-to-stand movement from a chair is a mechanically demanding component of activities of daily living. Here, we developed a novel method using the ground reaction force and center of pressure measured from the Nintendo Wii Balance Board to quantify sit-to-stand movement (sit-to-stand score) and investigated the age-related change in the sit-to-stand score as a method to evaluate reduction in motor performance. The study enrolled 503 participants (mean age ± standard deviation, 51.0 ± 19.7 years; range, 20–88 years; male/female ratio, 226/277) without any known musculoskeletal conditions that limit sit-to-stand movement, which were divided into seven 10-year age groups. The participants were instructed to stand up as quickly as possible, and the sit-to-stand score was calculated as the combination of the speed and balance indices, which have a tradeoff relationship. We also performed the timed up and go test, a well-known clinical test used to evaluate an individual’s mobility. There were significant differences in the sit-to-stand score and timed up and go time among age groups. The mean sit-to-stand score for 60s, 70s, and 80s were 77%, 68%, and 53% of that for the 20s, respectively. The timed up and go test confirmed the age-related decrease in mobility of the participants. In addition, the sit-to-stand score measured using the Wii Balance Board was compared with that from a laboratory-graded force plate using the Bland–Altman plot (bias = −3.1 [ms] -1 , 95% limit of agreement: −11.0 to 3.9 [ms] -1 ). The sit-to-stand score has good inter-device reliability (intraclass correlation coefficient = 0.87). Furthermore, the test–retest reliability is substantial (intraclass correlation coefficient = 0.64). Thus, the proposed STS score will be useful to detect the early deterioration of motor performance.

    DOI

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著書 【 表示 / 非表示

  • 関節外科(特集 運動器を扱うメディカルスタッフのためのバイオメカニクス必携)

    企画・編集:帖佐 悦男 (担当: 共著 )

    メジカルビュー社  2016年11月

  • 未来型人工関節を目指して -その歴史から将来展望まで―

    吉川秀樹, 他 (担当: 共著 , 担当範囲: pp.181-186 )

    日本医学館  2013年07月

  • 整形・災害外科 (特集 骨・関節のバイオメカニクス –最近の進歩)

    企画:黒坂昌弘 (担当: 共著 , 担当範囲: pp.1365-1374 )

    金原出版  2012年10月 ISBN: 0387-4095

  • 橈骨遠位端骨折 最近の進歩と治療法の選択

    斎藤英彦,他 (担当: 共著 , 担当範囲: pp.168-172 )

    金原出版  2010年07月

総説・解説記事 【 表示 / 非表示

工業所有権 【 表示 / 非表示

  • 運動器評価システム及び運動器評価方法

    特願 特願2015-185872  特許 特許第6281876号

    山子 剛,帖佐 悦男

  • 立ち上がり能力測定用の椅子及び立ち上がり能力評価システム

    特願 特願2014-240243 

    鄧 鋼,帖佐 悦男,山子 剛

科研費(文科省・学振)獲得実績 【 表示 / 非表示

  • 人工股関節全置換術後の生体力学的な未来予測

    基盤研究(C)

    研究期間:  2017年04月  -  2020年03月  代表者:  山子 剛

  • 術後の骨量減少が生じない傾斜低弾性人工股関節ステムの最適化研究(国際共同研究強化)

    国際共同研究加速基金(国際共同研究強化)

    研究期間:  2016年04月  -  2018年03月  代表者:  山子 剛

  • 術後の骨量減少が生じない傾斜低弾性人工股関節ステムの最適化研究

    若手研究(B)

    研究期間:  2014年04月  -  2016年03月  代表者:  山子 剛

  • 皮質骨の微細孔構造及び基質の石灰化が骨力学特性に及ぼす影響

    若手研究(B)

    研究期間:  2008年04月  -  2010年03月  代表者:  山子 剛

その他競争的資金獲得実績 【 表示 / 非表示

  • フォースプレートを用いた『ロコモ』モニタリングシステムの製品化

    提供機関:  国立研究開発法人 科学技術振興機構  JST マッチングプランナープログラム「探索試験」

    研究期間: 2015年04月  -  2017年03月  代表者:  山子 剛

  • 機械的強度と弾性率を部位毎に最適化させた新素材活用による新たな人工 股関節ステムの開発と事業化

    提供機関:  国立研究開発法人日本医療研究開発機構  AMED 医工連携事業化推進事業

    研究期間: 2014年04月  -  2017年03月 

  • マッチング研削システムによるMetal on metal型人工股関節摺動面の高精度クリアランス制御

    提供機関:  その他省庁等  中小企業庁 戦略的基盤技術高度化事業(サポイン)

    研究期間: 2013年04月  -  2014年03月 

  • Micro-CT装置を利用した骨石灰化度測定システムの開発

    提供機関:  国立研究開発法人 科学技術振興機構  JST シーズ発掘試験(A)

    研究期間: 2008年04月  -  2009年03月  代表者:  山子 剛

  • 大腿骨髄外アライメントガイドの研究開発

    提供機関:  国立研究開発法人 科学技術振興機構  JST 研究成果実用化検討(FS)課題

    研究期間: 2007年04月  -  2008年03月  代表者:  山子 剛

研究発表 【 表示 / 非表示

  • Effect of Young's modulus Gradient in Ti-33.6Nb-4Sn Femoral Stem on Bone Remodeling and Interface Stress.

    Go Yamako, Dennis Janssen, Shuji Hanada, Thomas Anijs, Kiyohide Ochiai, Koji Totoribe, Etsuo Chosa, Nico Verdonschot.

    ORS 2018 Annual Meeting  2018年03月  -  2018年03月   

  • Hip Joint Reaction Force on the Healthy and Diseased side of Patients with Unilateral Hip Osteoarthritis Exhibited the Trendelenburg-Duchenne Sign.

    Koki Ouchi, Gang Deng, Go Yamako, Koji Totoribe, Etsuo Chosa.

    ORS 2018 Annual Meeting  2018年03月  -  2018年03月   

  • Evaluation of Contact Area and Pressure on Total Surface Bearing Sockets during Gait and Stair Ascent and Descent in Two Subjects.

    Koji Totoribe, Etsuo Chosa, Go Yamako, Xin Zhao, Hiroaki Hamada, Koki Ouchi, Gang Deng.

    ORS 2018 Annual Meeting  2018年03月  -  2018年03月   

  • Trendelenburg跛行を呈する片側変形性股関節症患者を対象とした健側と患側の股関節反力の検討

    大内宏輝,Deng Gang,山子 剛,鳥取部光司,帖佐悦男

    第44回日本臨床バイオメカニクス学会  2017年11月  -  2017年11月   

  • 有限要素法による寛骨臼上脆弱性骨折の力学的評価

    山下柊太郎,山子 剛,田中秀逹,森 優,井樋栄⼆,帖佐悦男

    第44回日本臨床バイオメカニクス学会  2017年11月  -  2017年11月   

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