25 research outputs found
Changes in the body-weights and subscapular skinfold thicknesses of members of an Antarctic expedition
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The use of the South African frog (Xenopus laevis) in the study of spinal reflex physiology
The use of the South African frog (Xenopus laevis) in studies on spinal neurophysiology is introduced for the study of monosynaptic reflexes. Motorneurone excitability in this species may be measured by the classical procedure of monosynaptic testing. Operational procedures for exposing the spinal cord and the roots of the spinal nerves are described. Detailed information on stimulating and recording techniques which have been found satisfactory for the South African frog are given.The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format
New clinical prediction model for early recognition of sepsis in adult primary care patients:a prospective diagnostic cohort study of development and external validation
Background Recognising patients who need immediate hospital treatment for sepsis while simultaneously limiting unnecessary referrals is challenging for GPs.Aim To develop and validate a sepsis prediction model for adult patients in primary care.Design and setting This was a prospective cohort study in four out-of-hours primary care services in the Netherlands, conducted between June 2018 and March 2020.Method Adult patients who were acutely ill and received home visits were included. A total of nine clinical variables were selected as candidate predictors, next to the biomarkers C-reactive protein, procalcitonin, and lactate. The primary endpoint was sepsis within 72 hours of inclusion, as established by an expert panel. Multivariable logistic regression with backwards selection was used to design an optimal model with continuous clinical variables. The added value of the biomarkers was evaluated. Subsequently, a simple model using single cut-off points of continuous variables was developed and externally validated in two emergency department populations.Results A total of 357 patients were included with a median age of 80 years (interquartile range 71–86), of which 151 (42%) were diagnosed with sepsis. A model based on a simple count of one point for each of six variables (aged >65 years; temperature >38°C; systolic blood pressure ≤110 mmHg; heart rate >110/min; saturation ≤95%; and altered mental status) had good discrimination and calibration (C-statistic of 0.80 [95% confidence interval = 0.75 to 0.84]; Brier score 0.175). Biomarkers did not improve the performance of the model and were therefore not included. The model was robust during external validation.Conclusion Based on this study’s GP out-of-hours population, a simple model can accurately predict sepsis in acutely ill adult patients using readily available clinical parameters
An investigation into essential aspects of posture in primary school boys and male senior executives
The purpose of this study was to investigate the incidence and extent of postural defects in a group of 43 middle aged senior executives from two large companies, and 58 primary school boys from rural areas. The first group had a sedentary lifestyle while the second was selected to attend an annual sports training workshop at the Sports Institute of the University of Pretoria. Postures of the subjects were analysed by means of photographic images using the pro forma of Barlow (1956, 1990). The majority of the executives had malposture with 2.3%, 23.3%, 58.1% and 16.3% and 6.3% of the subjects being categorised with slight postural defects, severe postural defects, very severe postural defects and gross deformity, respectively. The values of the primary school boys for the same categories were 3.4%, 20.7%, 48.3% and 27.6%. None of the subjects studied was categorised as being without any postural defects. The results support others in this field (Cochrane, 1924; Dart, 1947; Kiernander, 1956; Lawson-Wood & Lawson-Wood, 1977; Barlow, 1990) who observed that malposture is common in both children and adults. The most common postural defect found in both groups were kyphosis (100% in adults and 89.7% in primary school boys) and lordosis (70% in adults and 93.1% in primary school boys). Barlow (1956; 1990) in a study on various groups, found that students in Physical Education had worse postures than other students. In the present study 75.9% of the primary school boys had either very severe postural defects or gross deformity against a value of 62.4% in the male senior executives, supporting the findings of Barlow (1956; 1990) to some extent.
(S. African J. for Research in Sport, Physical Ed. and Recreation: 2001 23 (1): 37-50
Prevalence and distribution of muscle-imbalance in the human body: A review
For more than a century it has been recognized that variations from normal in the anatomy and biomechanics of man may have a practical bearing on medical problems. In this paper an aspect of this kind of deviation namely muscle-imbalance, is reviewed. Muscle-imbalance could be defined as a specific movement dysfunction, which manifests itself in muscles that tend to become tight, or short and hypertonic and are readily activated in most movement patterns. Other muscles react by inhibition, inhibition atrophy and weakness. Muscle groups can functionally be divided into muscles prone to tightness and those prone to weakness. The phenomenon of muscle imbalance is pandemic, and may contribute to problems such as poor posture, low back pain. Significant is the fact that muscle imbalance may influence the motor patterning process.
Key words: Muscle imbalance, low back pain, posture, malposture, withdrawal response.
(Af. J. Physical, Health Education, Recreation and Dance: 2002 8(1): 49-60
Dynamic electrical muscle stimulation (EMS) training of the quadriceps femoris
Previous research on muscle strengthening using electrical stimulation has mainly focused on isometric training. Thus, the aim of the study was to investigate the effect of isokinetic and isotonic electrical muscle stimulation training on the strength of the quadriceps femoris muscle group. A quantitative, experimental, comparative, research design, making use of a pre-test, treatment period, and post-test, was used. Subjects were divided into two experimental groups and one control group: Group A (isokinetic NMES group), Group B (isotonic NMES group) and Group C (control group). The non-dominant knee extensors of 24 subjects were assessed for peak torque by means of a Cybex 340 isokinetic dynamometer at angular velocities of 0°/s (at 60° of knee flexion), 60, 180, and 240°/s, before and after the experimental treatment period of 10 sessions. An ENDOMED CV-405 electrical muscle stimulator was used to administer the NMES training in Groups A and B. Dependent t-tests and Duncan's Multiple Range Test for Variance revealed that both isotonic and isokinetic electrical stimulation training resulted in significant knee extension torque improvements. Group A showed significant (p < 0.05) improvements of 13 to 21% at the angular velocities tested, while Group B showed significant (p < 0.05) improvements of 11.5, 7.5, and 19.5% at angular velocities of 0, 60, and 180°/s, respectively. Group C also showed a significant (p < 0.05) improvement of 6%, but only at 0°/s. Thus, isokinetic and isotonic electrical muscle stimulation training was shown to be effective in improving the muscle strength of the quadriceps femoris.
Key words: Electrical muscle stimulation, strength training, isokinetic, isometric, peak torque, muscle strength, quadriceps femoris.
(Af. J. Physical, Health Education, Recreation and Dance: 2003 Special Edition: 173-182
Effects of 8 weeks resistance training on serum lipids in sedentary male smokers
In order to evaluate the effect of dynamic resistance training (DRT) on lipid profiles, 28 sedentary male smokers (mean age 28 years, 7 months) were randomly placed into a control group (CG) (n = 15) or an experimental group (EG) (n = 13). While the CG took part in no structured exercise throughout the eight-week period, the EG exercised using DRT for the eight weeks (nine exercises were performed at 60% of one repetition maximum, three times per week, non-consecutively) and were monitored for changes in lipid profiles. Although the independent and paired t-tests demonstrated no statistically significant changes in any of the measured lipid profile concentrations, the following changes were observed: decreases in total cholesterol (0.52%) and low-density lipoprotein cholesterol (2.95%), and increases in triglycerides (1.96%) and high-density lipoproteins (4.41%). The lack of statistically significant changes in the individual lipid parameters could not have been affected by diet, cigarettes smoked daily, aerobic fitness and/or body mass, since these parameters did not change significantly from the pre- to post-test measures.
Key words: Cholesterol, male smokers, high-density lipoproteins (HDL), lipids, low-density lipoproteins (LDL), resistance training, triglycerides (TG).
(Af. J. Physical, Health Education, Recreation and Dance: 2003 Special Edition: 148-157
Abdominal fat distribution and cardiovascular risk factors in hypertensive females
The link between abdominal fat distribution and insulin related cardiovascular risk factors in black and white female hypertensives who were on drug treatment for hypertension was investigated with computed tomography scan, sonar, anthropometric measurements and blood testing. Fasting blood samples were tested for: insulin, glucose, triglyceride, apoprotein B, apoprotein A1, total cholesterol, HDL cholesterol, lipoprotein a, uric acid, fibrinogen and plasminogen activity. Albumin and creatinine were measured in urine samples. Black subjects were slightly more obese than their white counterparts as judged from their body mass indexes (34.39±6.60 vs. 32.08±6.77 kg/m2,
A comparison of three different methods for the measurement of hamstring flexibility
Various tests are utilized within the field of sport science and biokinetics to measure hamstring flexibility. Within this explorative study, three methods were compared and the results correlated in order to establish the interchangeable use of these methods. A parametric comparative experimental research design was utilized. Forty male soccer players with a mean age of 21.29 years (± 2.48) were used as subjects. The subjects were divided into three groups and tested on 3 separate days, 4 days apart. The same researcher performed the testing to prevent intra-tester variability. The various techniques used to determine hamstring muscle flexibility were: (1) the straight leg raise method (SLR), (2) the active knee extension method (AKE), and (3) the hip roll method. Descriptive statistics was used to determine group means, modes, medians, standard deviations, etc. and single factor analysis of variance (ANOVA) was used to determine the significance of the potential differences at a 0.01 significance level. Hamstring flexibility for the right leg was 87.25° (± 7.81) for the SLR (or 2.75° knee flexion), 42.052° of knee flexion (± 7.24) for the hip roll method, and 49.13° of knee flexion for the AKE method. Hamstring flexibility for the left leg was 86.95° (± 7.82) for the SLR (or 3.05° of knee flexion), 41.3° of knee flexion (± 6.599) for the hip roll method, and 45.95° of knee flexion for the AKE method. The results of the present study indicated significant differences (