Simulation of Human Body Motion under the Condition of Weightlessness

Wei Kailai,Yoshihiko Tagawa,Naoto Shiba 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Astronauts’ patterns of work under the condition of weightlessness and their adaptability thereto are important topics of space research in the field of manned space flight technology. In space, astronauts experienceweightlessness, which is a very different condition from that experienced on the earth’s surface, and space flight tasks are performed at nearly 0 G. In this report, we describe the application of MATLAB Simulink and SimMechanics to the simulation andcalculation of motion in weightlessness. The simulation results and the theoretical analysis are compared to prove that the centroid of the whole human body remains unchanged in the free motion state in space. This model can beapplied to various computations of human motion under the condition of weightlessness. It can generate reference datafor research into fields such as human space flight and space medicine. Furthermore, with certain modifications, itcan be used to simulate and calculate human motion under normal as well as excessive gravity.

The clinical outcomes of infraspinatus rotational transfer for irreparable posterosuperior rotator cuff tears: a preliminary report

Harada, Nobuya,Ishitani, Eiichi,Gotoh, Masafumi,Shiba, Naoto Korean Shoulder and Elbow Society 2022 대한견주관절의학회지 Vol.25 No.3

Background: This study aimed to examine the preliminary clinical results of the infraspinatus rotational transfer procedure for irreparable posterosuperior rotator cuff tears. Methods: This study included 34 patients (mean age, 68.4 years). Their mean tear width and length measurements were 50.9 mm and 50.6 mm, respectively. The functional outcomes, including physician-determined and patient-reported scores, were evaluated before and at 1 year after surgery. The structural outcomes determined using the magnetic resonance imaging examination results were also assessed. Results: The clinical scores significantly improved after surgery compared with the scores before surgery: the Constant-Murley score (53.3±21.1 to 76.8±10.5), University of California at Los Angeles Shoulder score (15.6±3.6 to 27.8±6.7), American Shoulder and Elbow Surgeons Shoulder score (51.8±18.3 to 89.1±13.5), and WORC score (925.0±436.8 to 480.3±373.2) (all p<0.001). Postoperative re-tears were noted in two patients (5.9%). Conclusions: One year postoperatively, the patient's clinical scores significantly improved, with a re-tear rate of 5.9%.

Posterior decentering of the humeral head in patients with arthroscopic rotator cuff repair

Hidehiro Nakamura,Masafumi Gotoh,Hirokazu Honda,Yasuhiro Mitsui,Hiroki Ohzono,Naoto Shiba,Shinichiro Kume,Takahiro Okawa 대한견주관절학회 2022 대한견주관절의학회지 Vol.25 No.1

Background: In some patients with rotator cuff tear (RCT), the axial view of magnetic resonance imaging (MRI) shows subtle posterior decentering (PD) of the humeral head from the glenoid fossa. This is considered to result from a loss of centralization that is typically produced by rotator cuff function. There are few reports on PD in RCT despite the common occurrence of posterior subluxation in degenerative joint disease. In this study, we investigated the effect of PD in arthroscopic rotator cuff repair (ARCR). Methods: We conducted a retrospective study of consecutive patients who underwent ARCR at our institute and were followed-up for at least 1 year. PD was identified as a 2-mm posterior shift of the humeral head relative to the glenoid fossa in the axial MRI view preoperatively. The tear size and fatty degeneration (FD, Goutallier classification) were also evaluated using preoperative MRI. Retears were evaluated through MRI at 1 year postoperatively. Results: We included 135 shoulders in this study. Ten instances of PD (including seven retears) were observed preoperatively. Fifteen retears (three and 12 retears in the small/medium and large/massive tear groups, respectively) were observed postoperatively. PD was significantly correlated with tear size, FD, and retear occurrence (p<0.01 each). The odds ratio for PD in retears was 34.1, which was greater than that for tear size ≥3 cm and FD grade ≥3. Conclusions: We concluded that large tear size and FD contribute to the occurrence of PD. Furthermore, PD could be a predictor of retear after ARCR.

Clinical outcome in patients with hand lesions associated with complex regional pain syndrome after arthroscopic rotator cuff repair

Takaki Imai,Masafumi Gotoh,Keiji Fukuda,Misa Ogino,Hidehiro Nakamura,Hiroki Ohzono,Naoto Shiba,Takahiro Okawa 대한견주관절의학회 2021 대한견주관절의학회지 Vol.24 No.2

Background: Complex regional pain syndrome (CRPS)-related hand lesions are one of the complications following arthroscopic rotator cuff repair (ARCR). This study aimed to investigate the clinical outcomes of patients with CRPS-related hand lesions following ARCR. Methods: Altogether, 103 patients with ARCR were included in this study (mean age, 63.6±8.2 years; 66 males and 37 females; follow-up period, preoperative to 12 months postoperative). Clinical assessment included the Japanese Orthopaedic Association (JOA) score, University of California, Los Angeles (UCLA) score, Constant score, 36-item short form health survey (SF-36) score, and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score from preoperative to 12 months postoperatively. The patients were either assigned to the CRPS group or non-CRPS group depending on CRPS diagnosis until the final follow-up, and clinical outcomes were then compared between the groups. Results: Of 103 patients, 20 (19.4%) had CRPS-related hand lesions that developed entirely within 2 months postoperatively. Both groups showed significant improvement in JOA, UCLA, and Constant scores preoperatively to 12 months postoperatively (p<001). Comparisons between the two groups were not significantly different, except for SF-36 “general health perception” (p<0.05) at 12 months postoperatively. At final follow-up, three patients had residual CRPS-related hand lesions with limited range of motion and finger edema. Conclusions: CRPS-related hand lesions developed in 19.4% of patients following ARCR. Shoulder or upper-limb function improved in most cases at 12 months, with satisfactory SF-36 patient-based evaluation results. Patients with residual CRPS-related hand lesions at the last follow-up require long-term follow-up.

Extracorporeal Shock Wave Therapy and a New Assessment Tool for Intractable Wounds of the Limbs

Takuro Sugiyama,Murakami Hidetaka,Noguchi Koji,Kawano Koji,Shibata Minami,Shiba Naoto 대한창상학회 2023 Journal of Wound Management and Research Vol.19 No.1

Background: Extracorporeal shock wave therapy (ESWT) is indicated for intractable skin wounds and skin ulcers; however, assessing its efficacy for wounds at the periphery of the extremities may be difficult depending on the wound size (small wounds are challenging to differentiate over time with existing scores) and due to unclear metrics for assessing the amount of exudate and inflammation. To overcome this issue, we developed the Hand and Foot Wound Assessment Tool (HFWAT), comprising area and size, necrotic tissue and healthy granulation tissue, depth, amount of exudate, and inflammation and signs of infection. This study aimed to examine the effect of ESWT on obliterating limb wounds and evaluate outcomes using the HFWAT.Methods: The study included seven patients (four males, three females; 63.4±14.0 years) who visited our hospital between April 2018 and March 2020 and presented with persistent skin wounds on the hands and feet that did not heal despite treatment for more than 2 weeks. Patients received an energy flux density of 0.01 mJ/mm2, which was gradually increased. The HFWAT was used to evaluate the wound, and the pre- and post-ESWT scores were compared.Results: Successful wound healing was observed in all patients following ESWT. The median HFWAT score improved from 9.0 (interquartile range, 9–10) points before ESWT to 0.0 (interquartile range, 0–0) points at the final evaluation (P=0.05, n=7).Conclusion: ESWT was effective for intractable wounds, as demonstrated by the significantly improved HFWAT score. Furthermore, the HFWAT could be valuable for assessing small wounds in the peripheral extremities.

Clinical results of conservative management in patients with full-thickness rotator cuff tear: a meta-analysis

Masaki Karasuyama,Masafumi Gotoh,Keiji Tahara,Junichi Kawakami,Kazuya Madokoro,Takashi Nagamatsu,Takaki Imai,Nobuya Harada,Yu Kudo,Naoto Shiba 대한견주관절학회 2020 대한견주관절의학회지 Vol.23 No.2

Background: Several systematic reviews have reported on the conservative treatment of full-thickness rotator cuff tears; however, clinical results of this treatment still remain determined. Methods: PubMed, Cochrane Library, PEDro, and CINAHL databases were systematically searched for randomized clinical trials and observational studies. Two independent researchers reviewed a total of 2,981 articles, 28 of which met the criteria for inclusion in the study. Clinical outcome measures included Constant score, visual analog scale score for pain, range of motion, and short-form 36. The meta-analysis used a linear mixed model weighted with the variance of the estimate. Results: The meta-analysis showed a significant improvement after surgery. Pain score is 26.2 mm (1 month) to 26.4 mm (3 months) and 24.8 mm (12 months) (P

Effect of suprascapular nerve injury on muscle and regenerated enthesis in a rat rotator cuff tear model

Kenichiro Eshima,Hiroki Ohzono,Masafumi Gotoh,Hisao Shimokobe,Koji Tanaka,Hidehiro Nakamura,Tomonoshin Kanazawa,Takahiro Okawa,Naoto Shiba 대한견주관절의학회 2023 대한견주관절의학회지 Vol.26 No.2

Background: Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model. Methods: Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (–) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively. Results: SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (–) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (–) group. The bone-tendon junction enthesis was firm in the SN injury (–) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon–bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups. Conclusions: In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs.

Neurotropin protects rotator cuff tendon cells from lidocaineinduced cell death

Ryunosuke Abe,Hiroki Ohzono,Masafumi Gotoh,Yosuke Nakamura,Hirokazu Honda,Hidehiro Nakamura,Shinichiro Kume,Takahiro Okawa,Naoto Shiba 대한견주관절의학회 2021 대한견주관절의학회지 Vol.24 No.4

Background: Local anesthetics often are used in rotator cuff tears as therapeutic tools, although some cases have reported that they have detrimental effects. Neurotropin (NTP) is used widely in Japan as a treatment for various chronic pain conditions and is shown to have protective effects on cartilage and nerve cells. In this study, we investigated the protective effect of NTP against lidocaine-induced cytotoxicity. Methods: Tenocytes from rotator cuff tendons were incubated with lidocaine, NTP, lidocaine with NTP, and a control medium. Cell viability was evaluated using the WST-8 assay. Cell apoptosis was detected via annexin V staining using flow cytometry. The expression of BCL-2 and cytochrome c, which are involved in the intrinsic mitochondrial pathway of apoptosis, was evaluated via Western blotting and immunohistochemical staining. Results: In the cell viability assay, lidocaine decreased cell viability in a dose-dependent manner, and NTP did not affect cell viability. Moreover, NTP significantly inhibited the cytotoxic effect of lidocaine. The flow cytometry analysis showed that lidocaine significantly induced apoptosis in tenocytes, and NTP considerably inhibited this lidocaine-induced apoptosis. Western blotting experiments showed that lidocaine decreased the protein expression of BCL-2, and that NTP conserved the expression of BCL-2, even when used with lidocaine. Immunohistochemical staining for cytochrome c showed that 0.1% lidocaine increased cytochrome c-positive cells, and NTP suppressed lidocaine-induced cytochrome c expression. Conclusions: NTP suppresses lidocaine-induced apoptosis of tenocytes by inhibiting the mitochondrial apoptotic pathway. Intra-articular/bursal injection of NTP with lidocaine could protect tenocytes in rotator cuff tendons against lidocaine-induced apoptosis.