Biomechanical Study on the Effect of Muscle Strength on Contact Characteristics of Foot Joints / 医用生物力学

Objective To explore the effect of mucle force on contact force, peak pressure and contact area of foot joint in in vitro biomechanical experiment of foot and ankle, so as to provide references for choosing appropriate loading modes. Methods In neutral position of the ankle joint, fresh calf and foot specimens were simulated with or without mucle force loading. The contact force, peak pressure and contact area of the 1st metatarsophalangeal joint, the 2nd metatarsophalangeal joint, the 1st tarsometatarsal joint, the 2nd tarsometatarsal joint, the medial cuneonavicular joint, the intermediate cuneonavicular joint, the talonavicular joint, the calcicocuboid joint, the subtalar joint ( posterior articular surface) and the tibiotalar joint of normal foot under loading were measured, the results are compared and analyzed. Results Under muscle force loading, the contact force of the 1st metatarsophalangeal joint, the 2nd metatarsophalangeal joint, the 1st tarsometatarsal joint,the 2nd tarsometatarsal joint, the medial cuneonavicular joint, the intermediate cuneonavicular joint, the talonavicular joint and the tibiotalar joint were significantly greater than those without muscle force loading (P<0. 05), and the change percentages were 719. 28% , 311. 37% , 128. 67% , 50. 82% , 54. 89% , 57. 63% ,79. 98% and 50. 34% , respectively. The peak pressures of the 1st metatarsophalangeal joint , the 1st tarsometatarsal joint and the talonavicular joint under muscle force loading were significantly higher than those without muscle force loading ( P < 0. 05), and the change percentages were 176. 14% , 62. 91% and 40. 07% ,respectively. The contact area of the 1st metatarsophalangeal joint, the 1st tarsometatarsal joint, the intermediate cuneonavicular joint and the subtalar joint ( posterior articular surface) under muscle force loading increased significantly (P<0. 05), and the change percentages were 132. 20% , 55. 41% , 30. 97% and 26. 87% , respectively. Conclusions In biomechanical experiment of foot and ankle specimens, muscle force loading has a significant effect on contact force, peak pressure and contact area of each foot joint, especially the forefoot.Therefore, it is necessary to consider the effect of muscle force loading on stress of foot and ankle in the study ofrelated in vitro specimens

Plantar pressure and gait characteristics in older adult patients with diabetes / 中国组织工程研究

BACKGROUND: Plantar pressure is one of the major risk factors for diabetic foot ulcers. OBJECTIVE: To explore the characteristics of plantar pressure under natural gait in older adult patients with diabetes and compare them with those in healthy older adults, providing data for preventing foot diseases and designing foot decompression products. METHODS: The study protocol was performed in accordance with the Medical Ethics Committee of Tianjin Medical University, China. Forty-one older adult patients with diabetes and 30 healthy older adults, both aged over 60 years, received plantar pressure detection using an insole-type root pressure measurement system. Peak plantar pressure, percentage of peak time, X offset, Y offset, 95% confidence ellipse area, step frequency, step velocity, stride length, standing phase, and swing phase were measured. After fully understanding the study protocol, each participant provided written informed consent. RESULTS AND CONCLUSION: Compared with healthy older adults, peak plantar pressure was significantly increased in the 2nd-4th metatarsal region, the peak time was decreased in most area of the left foot and increased in the right root heel and arch area in older adult patients with diabetes (P < 0.05). Compared with healthy older adults, standing phase was decreased, swing phase was increased, step frequency was decreased, stride length in males was increased, step velocity was increased, stride length in females was decreased, and step velocity was decreased in older adult patients with diabetes. Compared with healthy older adults, 95% confidence ellipse area was decreased, and X offset and Y offset were increased in older adult patients with diabetes. These results suggest that the stability and flexibility of older adult patients with diabetes are lower than those of healthy older adults. In older adult patients with diabetes, plantar pressure is obviously transferred from the heel to the humerus. Therefore, much attention should be paid to plantar pressure in foot care.

Analysis on Characteristics of Plantar Pressures in Different Age Groups during Walking / 医用生物力学

Objective To obtain kinetic parameters of the plantar pressure in different age groups during normal walking, so as to provide theoretical references for designing insoles and sports shoes for different age groups, and maximally minimize the risk of foot injuries. Methods Footscan force plate was used to test the peak plantar force and pressure of 120 subjects in 4 different age groups (15 male and 15 female in 20-30, 30-40, 40-50, 50-60 age group, respectively). Results The peak plantar force constantly changed with age, showing a rising tendency, except that at the first phalanx area, the peak plantar force gradually decreased with age. For female subjects, the peak plantar pressure in the first phalanx area was gradually decreasing. Most subjects had significantly higher force on the 2nd and 4th bones than the 1st and 5th metatarsals. The 2nd metatarsal peak plantar force in male 50-60 age group was also significantly higher than that in male 20-50 age group (P<0.05). Only the peak plantar force of the 1st phalanx gradually decreased with age increasing, and the rest of the plantar region showed an increasing tendency. A significant change in the peak plantar pressure was observed, especially in the 2nd and 3rd metatarsals, which showed a rising tendency (P<0.05). Conclusions The plantar force and pressure on each part of human foot constantly changed with age. To find out the characteristics of plantar pressures in different age groups can help to design corresponding sports shoes and exert the functions of sports shoes in a better way.

Effect of different doses of dexmedetomidine on blood pressure, heart rate and postoperative sedation in laparoscopic cholecystectomy / 医学研究生学报

Objective In laparoscopic cholecystectomy(LC), increased intra-abdominal pressure and carbon dioxide absorption may cause obvious sympathetic excitation and bring about increased blood pressure and heart rate. Effective control on such sympathetic responses can reduce complications, which is beneficial to timely recovery for patients. The study aimed to investigate the effect of different doses of dexmedetomidine on blood pressure, heart rate and postoperative sedation during perioperative period in patients undergoing LC.Methods Sixty patients enrolled in the study randomly were divided into three equal groups(20 patients each): control group(only equal amount of isotonic saline), low dose group and high dose group according to the injection of dexmedetomidine. At each time point including before anaesthesia(T0), before cutting(T1), pneumoperitoneum at 0min(T2), at 10min(T3), at 20min(T4), immediate deflation(T5), before extubation(T6), after extubation and before leaving operation room(T7), and entering recovery room(T8), records were made on the patient’s blood pressure, heart rate, SpO2, airway peak pressure, PetCO2 and Ramsay sedation score after extubation.Results Extubation time and PACU stay time were significantly longer in high dose group in comparison with control group and low dose group (F=12.669, P=0.000 and F=6.281, P=0.030 respectively). Compared with control group, the heart rates of high dose group and low dose group at T5, T7 and T8 decreased significantly(P<0.05). During T2-T5, airway peak pressure was significantly higher than those of control group and low dose group(P<0.05). At T7, the Ramsay score of high dose group was significantly higher than those of control group and low dose group(P=0.015).Conclusion Sustainable pumping of dexmedetomidine can keep stable heart rate. However, the increase of pumping rate and dose will deepen the depth of sedation after extubation and obviously extend extubation time and observation time in recovery room. Therefore, it is appropriate to infuse dexmedetomidine less than 0.5μg/(kg·h) in clinical anaesthesia.

The Tympanometric Norms for Children with Type A Tympanograms / 听力学及言语疾病杂志

Objective To study the reference values and related factors of tympanometry for children between 2 and 15 year-old .Methods From December 2014 to March 2015 ,a total of 120 children (240 ears total) among 2 to 15 year-old (6 .95-3 .12) with Type A tympanograms received the singe -frequency component tympanometry test ,including acoustic equivalent volume (Vea ) ,peak-compensated static admittance (Ytm ) ,tympanometric peak pressure (TPP) and tympanometric gradient (TG) .With the results of each test ,the relationships were conducted according to the differences of age and gender .The outcomes also were compared with the recent studies abroad .Re-sults The difference of TPP was statistically significant among the gender group ,and the differences of Vea and TPP were statistically significant between different age groups ,2-6 year pre-school children and 7~15 yr school children .Conclusion The normative values of each tests were significantly different between Chinese and western children of 2-15 years .We would speculate that the differences of TPP in the age and gender group have changed with the physiological characteristics of Eustachian tubes and eardrums and the differences among male and female .

The clinical applicationof amended concave position in gynecological laparoscopy surgery / 中国医学装备

Objective:To evaluate the clinical effects of amended concave position in gynecological laparoscopy surgery.Methods: Eighty ASAⅠ~Ⅱ patients with gynecological laparoscopy surgery were randomly divided into two groups, the patients in group A were adopted Trendelenburg position; the patients in group B were adopted amended concave position. The Ppeak and PETCO2 in the two groups were recorded during surgery, the time of extubation and the adverse effects as nausea, vomiting, shivering was recorded after surgery.Results: The Ppeak and PETCO2 of group A were higher than that of group B(t=2.526,t=2.838, t=2.881;P<0.05). The time of extubation of group A were higher than that of group B after surgery(t=2.515,t=2.436;P<0.05).Conclusion: Adopting amended concave position can reduce Ppeak and PETCO2 in gynecological laparoscopic surgery, and it is helpful for postoperative recovery of the patients with gynecological laparoscopy surgery.

High Frequency Tympanometry (1,000 Hz) for Neonates with Normal and Abnormal Transient Evoked Otoacoustic Emissions

BACKGROUND AND OBJECTIVES: This paper aimed at evaluating the characteristics of high-frequency (1,000 Hz) acoustic admittance (ya) for the neonates with transient evoked otoacoustic emissions (TEOAE) as either pass or refer group. SUBJECTS AND METHODS: Using a 1,000 Hz probe tone, 297neonates (152 male, 145 female aged 0–104 days old) were evaluated. Tympanometric parameters admittance value at +200 dapa, middle ear admittance, and tympanometric peak pressure were calculated for each tympanogram. RESULTS: The mean of ya was 0.9678 mmho in the TEOAE for the pass group and 0.7229 mmho in the refer group. The mean of acoustic admittance at +200 (y200) was 2.0657 in the TEOAE for the pass group and 1.7191 for the refer group. The mean of Tpp was 23/8591 in the TEOAE for the pass group and 59/7619 for the refer group. CONCLUSIONS: There were significant differences in the distribution of different types of tympanograms, the mean of ya, tympanic peak pressure, and y200 between the TEOAEs for the pass and the refer groups.

Analysis on potential risk of critical patients due to the difference of airway peak pressure of invasive ventilator in pressure controlled ventilation mode / 中国医学装备

Objective:To reveal the difference of airway peak pressure of different brands and models invasive ventilator in our hospital through test and analysis, and reveal that the difference might bring potential threat to the critical patients.Methods: Using adult simulated lung with adjustable respiratory resistance and compliance as the load of invasive ventilator to measure airway peak pressure of invasive ventilator in constant pressure controlled ventilation mode. Results: The results showed that the measured ventilators surely have differences in airway peak pressure in constant pressure controlled ventilation mode.Conclusion: For severe patients, if we ignore the peak airway pressure difference between invasive ventilators, there may be a threat to the critical patients.

The foot pressure distribution of a normal left and toes-out right foot gait / 中华物理医学与康复杂志

Objective To characterize the foot pressure distribution during walking of the male college students with a normal left foot and toes-out right foot gait.Methods Forty-two male college students age 20 to 25 with a toes-out gait on the right side and a normal gait on the left side were recruited.The FOOTSCAN system was used to measure their foot pressure distribution while walking.Results There were significant differences between the normal and the toes-out foot with regard to the peak pressure on the third metatarsal bone [(45.05 ±13.91)N/cm2 vs (26.83 ± 10.82) N/cm2] and pressure under the arch [(4.48 ± 1.94) N/cm2 vs (2.90 ±1.57) N/cm2],as well as the time for the appearance of peak pressure under the 1st and 4th metatarsal bones.The foot regional impulse was significantly lower on the normal side than on the toes-out side for toes 2 to 5 and for metatarsal bone 2.Conclusion In contrast to the normal foot,the pressure center of the toe-out foot deflects to the inner side.This results in slanted power application instead of straight ahead,so the strength in the direction of travel is small.And it will produce torsion between the tibia and fibula,which makes the tibia appear introverted and causes excessive friction in the knee joint.This will lead to injury of the knee joint.

Characteristics of Foot Pressure Distribution with or without Partial Prosthetic Foot in Transmetartarsal Amputee / 대한족부족관절학회지

PURPOSE: This study was designed to evaluate characteristics of foot pressure distribution with or without partial prosthetic foot in transmetatarsal amputee. MATERIALS AND METHODS: The subjects were 9 transmetatarsal amputees. Foot pressures were measured at hallux, the 1st-5th metatarsal head (MTH), mid-foot, condyle area by F-scan system in amputated or contralateral foot during active walking. RESULTS: In amputated foot, mean peak pressure was greatest in midfoot without prosthetic foot but it was greatest in hindfoot with prosthetic foot. In unaffected foot, although mean peak pressure was higher in hallux, and 1-5th MTH compared to amputated foot, it was greatest in hind foot both with and without prosthetic foot. However, in unaffected foot, mean peak pressure significantly decreased in hallux and 5th MTH after wearing the prosthetic foot. There was a significant difference in mean peak pressure in hallux and 5th MTH between amputated and unaffected foot after wearing prosthetic foot. However, other region had no significant difference with or without prosthetic foot between feet. CONCLUSIONS: The use of partial prosthetic foot tends to shift weight bearing from the heel area to forefoot and could significantly reduce hind foot peak pressure and redistributed to peak pressure. The partial prosthetic foot can also offer the peak pressure to reduction both amputated foot and unaffected foot and help to toe off during walking.

Dynamical Observation of Peak Pressure of Tympanogrom Before and After Radiotherapy for Nasopharyngeal Carcinoma / 听力学及言语疾病杂志

Objective To explore the changes of the peak pressure of tympanogrom in the first year before and after radiotherapy for Nasopharyngeal Carcinoma (NPC) and observe its effect to audition.Methods Acoustic immittance and audiometry were used to detect 64 ears of NPC patients at regular intervals (before, during,at the end of rediotherapy and 6,12 months after radiotherapy). The data were collected and analyzed with statistic methods. Results There were 9 ears with secretory otitis media after radiotherapy. The peak pressure of tympanogrom of other 55 ears was negative at the beginning of radiation, reached highest at the end of radiotherapy,the average was -30(-100, 5.0) daPa.Compared with the peak pressure of tympanogrom before radiation, there was significant statistic difference ( P =0.001). The peak pressure reached to the level of pre-radiation 12 months after radiation, 5.0(-2.5,10.0) daPa. The 2.0 kHz audiometric threshold of bone conduction was 21.4?5.7 dB in 55 ears, compared with the audiometric threshold before radiation, there was evident statistic difference (P

Test-Retest Differences and Assistive Function in Detecting Conductive Hearing Loss of lmpedance Audiometry

lmpedance audiometry requires physical modifications during the test, which might influence retest data. Therefore, in Order to interprete retest data meaningfully, the range of variation should be identified in each measure of impedence audiometry. The present study obtained data on the retest variation of peak pressure, acoustic reflex threshold, static compliance and earcanal volume in impedance audiometry. ln addition, the authors wanted to know whether or not impedance data would assist otolaryngologists in the detection of conductive hearing impairment. The variation of the retest data was not clinically nor statistically significant in the measurement except for those of ear canal volume. The data on ear canal volume also suggested that the ear canal increases in size during the teenage period and that male ear canals are larger than those of females in ears over 20 years of age. The impedance data assisted the otolaryngologist in the detection of conductive hearing impairment