Dynamic biomechanical effect of lower body positive pressure treadmill training for hemiplegic gait rehabilitation after stroke: A case report

BACKGROUND Lower body positive pressure(LBPP)treadmill has potential applications for improving the gait of patients after stroke,but the related mechanism remains unclear.CASE SUMMARY A 62-year-old male patient suffered from ischemic stroke with hemiplegic gait.He was referred to our hospital because of a complaint of left limb weakness for 2 years.The LBPP training was performed one session per day and six times per week for 2 wk.The dynamic plantar pressure analysis was taken every 2 d.Meanwhile,three-digital gait analysis and synchronous electromyography as well as clinical assessments were taken before and after LBPP intervention and at the 4-wk follow-up.During LBPP training,our patient not only improved his lower limb muscle strength and walking speed,but more importantly,the symmetry index of various biomechanical indicators improved.Moreover,the patient’s planter pressure transferring from the heel area to toe area among the LBPP training process and the symmetry of lower body biomechanical parameters improved.CONCLUSION In this study,we documented a dynamic improvement of gait performance in a stroke patient under LBPP training,which included lower limb muscle strength,walking speed,and symmetry of lower limb biomechanics.Our study provides some crucial clues about the potential dynamic mechanism for LBPP training on gait and balance improvement,which is related to rebuilding foot pressure distribution and remodeling symmetry of biomechanics of the lower limb.

Effects of lower body positive pressure treadmill on functional improvement in knee osteoarthritis:A randomized clinical trial study

BACKGROUND Knee joint pain and stiffness are the two main symptoms of knee osteoarthritis(OA)and thus restrict a patient’s activities,such as walking and walking up and downstairs.The lower body positive pressure(LBPP)treadmill as one of the emerging body weight support system devices brings new hope for exerciserelated rehabilitation for knee OA patients.AIM To investigate the biomechanical effects and the subjective clinical assessment of LBPP treadmill walking exercise when compared with conventional therapy in mild to moderate knee OA patients.METHODS Eighteen patients with mild-to-moderate knee OA were recruited in this randomized controlled trial(RCT)study.The eligible knee OA patients were randomly assigned to two groups:LBPP and control groups.The patients in the LBPP group performed an LBPP walking training program for 30 min/session per day,6 d per week for 2 wk whereas the patients in the control group performed walking on the ground for the same amount.All patients underwent clinical assessments and three-dimensional gait analysis at pre-and 2-wk post-treatment.RESULTS The Western Ontario and McMaster Universities Arthritis Index and visual analog scale scores in both the LBPP group and control group were found to decrease significantly at the post-treatment point than the pre-treatment point(LBPP:70.25±13.93 vs 40.50±11.86;3.88±0.99 vs 1.63±0.52;control:69.20±8.88 vs 48.10±8.67;3.80±0.79 vs 2.60±0.70,P<0.001).Moreover,compared with the control group,the LBPP group showed more improvements in walking speed(P=0.007),stride length(P=0.037),and knee range of motion(P=0.048)during walking,which represented more improvement in walking ability.CONCLUSION The results of our RCT study showed that the LBPP group has a greater effect on improving gait parameters than the conventional group,although there was no significant advantage in clinical assessment.This finding indicates that LBPP treadmill walking training might be an effective approach for alleviating pain symptoms and improving lower extremity locomotion in mild to moderate knee OA patients.

Lower body weight and female gender:Hyperphosphatemia risk factors after sodium phosphate preparations

Casals et al have reported an inverse correlation between serum phosphate and body weight after administration of sodium phosphate at a dose of 60 g. Our group has already described the relationship between body weight and hyperphosphatemia with these preparations, although our study was not quoted by Casals. We performed a pharmacokinetic study involving 13 volunteers who were divided into two groups on the basis of body weight： group I consisting of seven women with a median weight of 60 kg and group Ⅱ consisting of five men and one woman with a median weight of 119.2 kg. Group Ⅰdeveloped higher peak phosphate levels and maintained these levels above the subjects in Group Ⅱ for a prolonged time period despite adequate hydration being ensured with frequent monitoring of weight, fluid intake and total body weight. Our studydemonstrated that adequate hydration does not protect against the secondary effects of hyperphosphatemia. In the study by Casais et al, 66% of the study subjects were women, the correlation between serum phosphate and gender in their data also appears to be important. Women are at higher risk of acute phosphate nephropathy due to a diminished volume of distribution of the high dose of ingested phosphate. Decreased volume of distribution in women is due to diminished body weight. This is further compounded by decreased creatinine clearance in females.

Evaluation of global cardiac systolic performance and diastolic filling in central hypovolumia by lower body negative pressure with Doppler echocardiography

Objective ：To overall evaluate the change of global cardiac systolic performance and diastolic filling in hypovoleamia by LBNP, Methods：10 healthy male subjects were placed in a standard LBNP chamber. Baseline haemodynamic and echocardiographic measurements were made after a period of least 10 min resting supine within the chamber. Pressure was then decreased to -10,-20 and -30 mmHg, with each pressure maintained for 15 rain. The indices of four transvalvular and SVC flow were measured using Doppler echocardiography. Results ：The results showed that S wave, Re wave ,and VTI of SVC progressively decreased with increasing LBNP. At -30 mmHg stage, S wave decreased by 35.4 % （change of 0.21±0.03 m/s, P 〈 0.001）. This reduction in pre-load Was associated with a progressive decrease in SV（by 21.5 ± 4.5 ml at -30 mmHg,P 〈 0.001 ）, decrease in CO（by 1.2 ± 0.2 L min^-1 at -30 mmHg LBNP,P 〈 0.001 ）. The diastolic filling of mitral and tricuspid flow also reduced significantly. At -30 mmHg stage, the E wave of MVF and TVF decreased 31% and 32% respectively （change of 0.23 ± 0.05 m/s,P 〈 0.001 and 0.18 ± 0.01 m/s,P 〈 0.001）. VTI of MVF and TVF decreased 27% and 27.7% respectively（change of 5.55 ± 1.41cm,P 〈 0.01 and 4.25 ± 0.44 cm,P 〈 0.01）. A wave of both sides did not change significantly. Conclusion：Doppler indices changes in different LBNP stage can roughly reflect the degree of hypovoleamia caused by blood volume redistribution. The indices of Doppler echocardiography are more sensitive than traditional physiological indexes in evaluating cardiovascular responses of LBNP. Echocardiography techniques overall can evaluate the global cardiac function including systolic performance and diastolic filling.

Surgical circumferential contouring:lower body,upper body,and in-between

Deformities in the body contouring population are rarely isolated to one area,and procedures can be combined to achieve more substantial results.While there is no formula for optimal surgical sequencing and timing,there are certain principles which-when applied appropriately-can yield results that are reliable,aesthetically pleasing,and aligned with the patient’s desires and preferences.In this article,we outline our latest thinking in circumferential body contouring and how to integrate the lower body lift with procedures of the abdomen,upper body,breasts,back,and arms to achieve the complete 360°look.

Total-Ionizing-Dose-Induced Body Current Lowering in the 130 nm PDSOI I/O NMOSFETs

The body current lowering effect of 130 nm partially depleted silicon-on-insulator (PDSOI) input/output (I/O) n-type metal-oxide-semiconductor field-effect transistors (NMOSFETs) induced by total-ionizing dose is observed and analyzed. The decay tendency of current ratio of body current and drain current I-b/I-d is also investigated. Theoretical analysis and TCAD simulation results indicate that the physical mechanism of body current lowering effect is the reduction of maximum lateral electric field of the pinch-off region induced by the trapped charges in the buried oxide layer (BOX). The positive charges in the BOX layer can counteract the maximum lateral electric field to some extent.

DYNAMIC MODELING OF METAMORPHIC MECHANISM

The concept of metamorphic mechanism is put forward according to the changeof configurations from one state to another. Different configurations of metamorphic mechanism aredescribed through the method of Huston lower body arrays. Kinematics analyses for metamorphicmechanism with generalized topological structure, including the velocity, angular velocity,acceleration and angular acceleration, are given. Dynamic equations for an arbitrary configuration,including close-loop constraints, are formed by using Kane's equations. For an arbitrary metamorphicmechanism, the transformation matrix of generalized speeds between configuration zeta and zeta+1 isobtained for the first time. Furthermore, configuration-complete dynamic modeling of metamorphicmechanism including all configurations is completely established.

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload

Objective To determine whether reduction in central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-load or is due to arterial dilation. Methods We compared effects of NTG with those of lower body negative pressure (LBNP). Hemodynamic measurements were made at rest,during LBNP (10,20 and 30 mmHg,each for 15 min) and after NTG (10,30 and 100 μg/min,each dose for 15 min) in ten healthy volunteers. Cardiac pre-load,stroke volume and cardiac output were assessed by echocardiography. Central pressure augmentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30 μg/min) reduced pre-load (as measured by the peak velocity of the S wave in the superior vena cava) to a similar degree [by (26.8±3.8)% and (23.9±3.4)%,respectively]. Compared to LBNP,NTG reduced systemic vascular resistance [by (32.9±7.5)%,P<0.01],decreased peripheral and central pressure augmentation [by (20.8±3.4)% units and (12.9±2.9)% units,respectively,each P<0.01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.

The Minimum Number of Attempts for a Reliable Isometric Strength Test Score

Purpose The maximal isometric strength test is widely used in general,athletic,and clinical populations.However,this test has often been used without considering how many trials are needed or appropriate to obtain reliable test scores.Thus,the aim of this study was to examine the maximal isometric strength test in upper and lower body for the purpose of determining the reliability of best isometric strength score and the ideal number of trials for a reliable test score.Methods One hundred and twelve healthy adults were assigned to four different groups(elbow flexion with the vertical and horizontal forearm positions,knee flexion,and knee extension).After familiarization,all participants performed three maxi-mal isometric voluntary contractions with the designated muscle group.The reliability of best isometric strength test score was calculated using the intraclass correlation coefficients(ICC)from a one-way ANOVA model.The Spearman-Brown prophecy formula was used to identify the minimum number of trials needed.Results The reliability of the best maximal isometric strength test scores out of three trials were high(ICC=0.92 to 0.98).At least two trials of maximal isometric strength test for knee flexion and one trial for elbow flexion and knee extension would be necessary to achieve an acceptable reliability coefficient of 0.80.In addition,one trial of elbow flexion would be enough for women,but men would need two trials.Conclusions Our results suggest that overall,at least two trials would be necessary to test isometric strength in upper and lower body muscles in both sexes.