Reliability of Testing the Knee Extensors and Flexors in Healthy Adult Women Using a Cybex II Isokinetic Dynamometer

This work was supported by NIH grant P50-AR39221. The purpose of this study was to determine intraobserver and interobserver reliability using a Cybex II isokinetic dynamometer for the measurement of isometric and isokinetic strength (0, 60, 180, 300 degrees /sec) and endurance (240 degrees /sec) in 20 healthy untrained females. Subjects were randomly assigned to one of two testers. Intraobserver reliability coefficients for tester one and tester two ranged from 0.89 to 0.98 and 0.72 to 0.97, respectively. Interobserver reliability coefficients ranged from 0.69 to 0.95 across speeds and movements. Although the testers differed significantly in reliability (p < 0.01), no systematic differences in measured levels of performance were noted between testers one and two for the majority of the measurements. The results indicate that comparable muscular strength and endurance values can be obtained from knee extension/flexion tests at various speeds using a Cybex II isokinetic dynamometer. Comparable values were obtained whether subjects were tested by a single tester on two separate occasions or whether subjects were tested by a different tester on two separate occasions. J Orthop Sports Phys Ther 1991;14(1):37-41.     

Maximum Grip Strength Is Not Related to Bone Mineral Density of the Proximal Femur in Older Adults

In the past decade there have been numerous publications reporting a significant and direct relationship between handgrip strength and bone mineral density (BMD) of the proximal femur in older adults. The present report challenges the appropriateness of the methods, and thus the conclusions used in these studies. Specifically, these studies failed to control for the concomitant influence of body weight on both BMD and muscle strength. In the present study, maximum handgrip strength was measured using a conventional hand-held hydraulic dynamometer. Bone mineral density of the proximal femur was measured using dual-energy X-ray absorptiometry (DXA). Using allometric scaling, the influence of body weight on the value of maximum handgrip strength was removed for the data of the women. A small, but significant relationship between BMD of the proximal femur and maximum handgrip strength was found that accounted for about 6% of the total variation. The relationship between BMD of the proximal femur and unscaled maximum handgrip strength was not significant for the men. The findings diminish the confidence in a protective effect of skeletal muscle on some nonadjacent skeletal structures and suggest that these relationships may benefit from being revisited. The results highlight the utility of allometric scaling in analyses in which the relationship between a physiological variable and a body dimension variable can be nonlinearly and simultaneously influenced by other body dimension variables that are not considered in the analysis and therefore are statistically uncontrolled. Received: 21 October 1997 / Accepted: 22 September 1998     

The Reliability of One vs. Three Trials of Pain-free Grip Strength in Subjects with Rheumatoid Arthritis

Study DesignMeasurement Reliability. The purpose of the study was to evaluate the test–retest reliability of one vs. the mean of three trials of pain-free grip strength in participants with rheumatoid arthritis (RA). The study used was a repeated-measures, crossover design. Pain-free grip strength was measured with the Biometric E-Link Evaluation System V900S (Unit 25, Nine Mile Point Ind. Est., Gwent UK NP11 7HZ), pain levels recorded before and after grip tests with visual analog scale. High levels of test–retest reliability (intraclass correlation coefficient ≥ 0.91) were found for both one trial and the mean of three trials of pain-free grip strength testing. Median values of grip strength for both methods produced comparable results. Clinically small but statistically significant increases in pain (p ≤ 0.01) were found. One trial of pain-free grip strength is reliable and may save valuable clinical time while reducing the assessment burden placed on patients with RA.Level of EvidenceN/A.     

Intrastriatal Grafts From Multiple Donors Do Not Result in a Proportional Increase in Survival of Dopamine Neurons in Nonhuman Primates

We examined the potential for “double grafts,” i.e., grafts from two donors in each recipient, to enhance the total number of ventral mesencephalic dopamine neurons that survive grafting in adult African green monkeys. Because dopamine cell survival in grafts represents a small percentage of the total number of neurons grafted, several human clinical trials recently have employed grafts of tissue from multiple donors (e.g., from two to eight embryos per host recipient) in attempts to increase the total number of dopamine neurons that survive in grafts. Presumably, this is intended to elevate dopamine levels by providing more dopamine neurons to the damaged brain to alleviate the symptoms of parkinsonism. While well-developed grafts with several thousand dopamine neurons were found in most recipient animals, we observed a reduced total number of tyrosine hydroxylase positive neurons in the grafts in spite of the presence of some double grafts that were larger than normal. The overall growth of the grafts was impressive; some grafts were so large that they spanned the full dorsoventral extent of the caudate nucleus, probably reflecting the fact that twice as much tissue was implanted in each drop site in comparison to our standard protocol. However, some animals revealed atypical patterns of neurite outgrowth that appeared limited to the grafted tissue, and at least one monkey revealed “amorphous” grafts generally lacking in cellular structure, which suggests a possible rejection phenomenon. These findings raise questions about the use of multiple donors and suggest that the likelihood of rejection and/or cell death may be enhanced, which is of potential importance in the designof grafting strategies for clinical applications.     

Low Grip Strength is a Strong Risk Factor of Osteoporosis in Postmenopausal Women

Objective

To investigate the effect of grip strength on bone mineral density (BMD) in postmenopausal women. Low BMD is related to risk of fracture and falling is the strongest factor for fragility fractures. Handgrip strength is a reliable indicator of muscle strength and muscle strength is associated with falling.

Methods

For the present study 120 women were divided into two groups: those ≤65 years and those >65 years. Serum 25 hydroxyvitamin D (25OHD), BMD, and handgrip strength were measured to observe the effect of age on 25OHD, grip strength, and BMD, as well as the effect of 25OHD on grip strength and BMD. The correlation between grip strength and BMD was investigated.

Results

In the 120 patients, 25OHD was 24.31 ± 8.29 ng/mL. There were 37 cases with 25OHD <20 ng/mL and 83 cases with 25 OHD ≥20 ng/mL. The patients with 25OHD <20 ng/mL had significantly lower femoral neck BMD, most of them with a T score ≤?2.5 (P < 0.05). BMD measurement showed 66 patients with femoral neck T ≤?2.5, 30 cases with total hip T ≤?2.5 and 90 cases with lumbar BMD T ≤?2.5. The maximum grip strength in the group is 22.28 ± 6.17 kg. There were 38 cases with the maximum grip strength <20 kg and 82 cases with the maximum grip strength ≥20 kg. Patients >65 years had lower 25OHD, lower maximum grip strength, and lower BMD. The osteoporosis risk in postmenopausal women with a maximum grip strength <20 kg and who were >65 years was significantly elevated.

Conclusion

Handgrip strength and 25OHD decrease with aging in postmenopausal women. The patients with lower 25OHD level had significantly lower BMD of femoral neck. The patients with lower handgrip strength had significantly lower BMD of lumbar spine, femoral neck, and total hip. Grip strength measurement is the simplest muscle strength measurement method. Our study confirmed that low grip strength was correlated with low BMD and was a strong risk factor for osteoporosis in postmenopausal women.

     

Radiograph-Based Study of Gender-Specific Vertebral Area Gain in Healthy Children and Adolescents as a Function of Age,Height, and Weight

This study reports gender-specific vertebral area gain data from children and adolescents. Vertebral area was measured on lateral and anteroposterior thoracic and lumbar spine radiographs from 100 female and 100 male subjects aged 7–28 yr. T9, T11, T12, L1, and L2 X-ray area calculation was based on calculation of the area of the geometric figure of a trapezoid whose 2 nonparallel sides were equal in length, taking account of the waisted shape of the vertebrae. Both the boys and girls of our study population showed statistically significant dependence (p < 0.001) of vertebral area gain on chronologic age, height, and weight right through the end of puberty, and especially so up to age 15 yr. However, height and weight were clearly better predictors of lateral and anteroposterior vertebral area gain than was chronologic age. Once vertebral growth is complete by age 18 yr or so, the lateral vertebral areas of the male subjects—regardless of body weight and height—are, on average, 25% larger, and the anteroposterior areas up to 30% larger than those of their female counterparts. After adjusting for chronologic age, height, and weight however we did not find significant differences, between gender, in vertebral area of male and female subjects, neither among children younger than 11 yr nor adolescents ages of 12–14 yr and young adults older than 18 yr.     

The Concurrent Validity of a Hand-held versus a Stationary Dynamometer in Testing Isometric Shoulder Strength

Study designClinical Measurement-Validity.IntroductionValidity of the JTech PowerTrack II hand-held dynamometer (JTech; JTech Medical, Salt Lake City, UT) for measuring shoulder strength has yet to be established.Purpose of the StudyTo examine the concurrent validity of isometric strength scores obtained with the JTech PowerTrack II, and on a stationary dynamometer, the LIDO WorkSET (LIDO; LoredanBiomedical, West Sacramento, CA).MethodsThirty-eight subjects performed three maximal efforts of shoulder flexion, abduction, and external rotation on a single occasion on the two dynamometers. Two testers were randomly assigned to administer the tests.ResultsPearson correlations between the scores on the two dynamometers (r.0.81) indicated a good concurrent validity. Correlations were similar when the results were subdivided by tester or gender.ConclusionsThis study suggests that either the JTech PowerTrack II or LIDOWorkSET provide comparable scores for shoulder strength. Although not interchangeable because of the differences in units of measurement, the relative conclusions about strength should be similar, regardless of which instrument is used.Level of EvidenceNot applicable.     

Isoflurane and Halothane Increase Adenosine Triphosphate Preservation, but Do Not Provide Additive Recovery of Function after Ischemia, in Preconditioned Rat Hearts

Background: Brief ischemic periods render the myocardium resistant to infarction from subsequent ischemic insults by a process called ischemic preconditioning. Volatile anesthetics have also been shown to be cardioprotective if administered before ischemia. The effect of preconditioning alone and combined with halothane or isoflurane on hemodynamic recovery and preservation of adenosine triphosphate content in isolated rat hearts was evaluated.

Methods: Seven groups of isolated rat hearts (n = 6 each) were perfused in a retrograde manner at constant temperature and pressure. A latex balloon was placed in the left ventricle to obtain isovolumetric contraction. Heart rhythm, coronary flow, left ventricular pressure and its derivative dP/dt (positive and negative), and developed pressure were monitored. The hearts were paced at 300 beats per minute. Each heart was randomly allocated to (1) a time-control group that received no ischemia, (2) an untreated group that received 25 min of normothermic ischemia only, (3 and 4) an isoflurane group and a halothane group that received 40 min of anesthetic (2.2% and 1.5%, respectively) before ischemia; (5) a preconditioning group that received two 5-min periods of ischemia separated by 10 min of reperfusion before ischemia; or (6 and 7) a isoflurane + preconditioning group and a halothane + preconditioning group that received anesthetic for 10 min at concentrations of 2.2% or 1.5%, respectively, before two 5-min periods of ischemia separated by 10 min of reperfusion. All treated groups received 25 min of normothermic ischemia followed by 30 min of reperfusion.

Results: The time-control group remained hemodynamically stable for the entire experiment, and the adenosine triphosphate content was 18.3 +/- 1.7 (SEM) micro Meter/g at the end of 115 min. The untreated group had depressed recovery after 25 min of normothermic ischemia, and the developed pressure was significantly depressed and recovered only 30 +/- 9% (P < 0.001) of its preischemic value. There was also a significant increase in the incidence of ventricular fibrillation (P < 0.001). Adenosine triphosphate content was significantly lower in this group than in all other groups. Five minutes of ischemia in the preconditioning group had little effect on hemodynamics and decreased developed pressure only 6.4%. Halothane depressed developed pressure by 16 +/- 5% (P < 0.001), and isoflurane increased coronary flow by 145 +/- 9% (P < 0.001) but had no significant hemodynamic effect. The treated groups had significantly better recovery of postischemic function than did the untreated group. In the preconditioning group, developed pressure recovered to 85% of control and dP/dt+ to 87% of control. The addition of halothane or isoflurane to preconditioning did not provide additional functional recovery but did increase the level of adenosine triphosphate preservation (13.1 +/- 1.1 and 12.4 +/- 1.1 micro Meter/g, respectively).     

Weight Loss Prior to Bariatric Surgery Is Not a Pre-requisite of Excess Weight Loss Outcomes in Obese Patients

Background  

Although weight loss before bariatric surgery may carry advantages during the surgical procedure (decreased liver volume, operation duration, and blood loss), it is still debated whether it induces a greater long-term weight loss.     

Effects of a Prolonged Submersion on Bone Strength and Metabolism in Young Healthy Submariners

Submariners taking part in prolonged missions are exposed to environmental factors that may adversely affect bone health. Among these, relatively high levels of CO₂, lack of sunlight exposure affecting vitamin D metabolism, limited physical activity, and altered dietary habits. The aims of this study were to examine the effect of a prolonged submersion (30 days) on changes in bone strength using quantitative bone speed of sound and in markers of bone metabolism that include bone turnover (BAP, PINP, TRAP5b, and CTx) and endocrine regulators (serum calcium, PTH, and 25[OH]D) in a group of 32 young healthy male submariners. The prolonged submersion led to increases in body weight and BMI and to a decrease in fitness level. There was a significant decrease in bone strength following the submersion. Speed of sound exhibited continued decline at 4 weeks after return to shore and returned to baseline levels at the 6-month follow-up. There was a significant increase in circulating calcium level. PTH and 25(OH)D levels decreased significantly. Significant decreases were observed in both TRAP5b and CTx levels, markers of bone resorption, as well as in N-terminal propeptide of type I collagen (PINP), a bone formation marker. Prolonged submersion led to a significant decrease in bone strength, accompanied by an overall decrease in bone metabolism. Bone strength was regained only 6 months after return to shore. Prevention and/or rehabilitation programs should be developed following periods of relative disuse even for young submariners. The effects of repeated prolonged submersions on bone health are yet to be determined.     

Characteristics of Perianal Abscess and Fistula-in-Ano in Healthy Children

Background Probably because of the low frequency, perianal abscess (PA) and fistula-in-ano (FIA) in children older than 2 years have not been investigated except in those with a predisposing condition such as Crohn’s disease. This study aims to summarize our experience about the characteristics and treatment of PA and FIA in healthy children. Methods The charts of all children older than 24 months of age treated for PA and/or FIA from 1990 to 2003 were reviewed. Results We found 40 patients, 37 of them boys (92.5%), ranging from 2 to 14 years of age (average: 7.19 years). At the first examination, the diagnosis was PA in 36 patients (mean age: 6.8 years; range: 2.3–13 years), and FIA in 4 patients (mean age: 10.8 years; range: 6–14 years). The primary local treatment of PA was drainage (needle aspiration in 26 patients, and incision and drainage in 4 patients) and local care in 6 patients. All patients received antibiotics. Overall, 29 children (80.6%) had primary cure of the abscess. Evolution included recurrent abscess in 3 patients (8.3%) and FIA in 4 patients (11.1%). Crohn’s disease was diagnosed in only one boy with an abscess of long duration. No patient developed a new PA in another location or a recurrent FIA. Four male patients aged 6 to 14 years (range: 7.1 years) had a FIA of long duration. One patient underwent a fistulectomy. Crohn’s disease was found in three other children and treated conservatively. Conclusion Drainage of PA by needle aspiration associated with antibiotics is effective in children older than 2 years of age with a low rate of evolution toward FIA. Associated pathology must be ruled out in children with FIA.     

健康教育在门诊患儿输液过程中的实施与评价

对796例患儿及613名家长健康教育需求进行评估,并根据评估结果采取针对性的健康教育。结果患儿和／或家长对各项护理知识的掌握及知晓率均≥90．0％,输液治疗依从性100％。提出健康教育应灵活运用教育方式,细心实施,及时评价。     

The Effects of Visual Feedback on Performance in Heart Rate- and Power-Based-Tasks during a Constant Load Cycling Test

Performance feedback can be essential for cyclists to help with pacing their efforts during competitions and also during standardized performance tests. However, the choice of feedback options on modern bike computers is limited. Moreover, little research on the effectiveness of the currently used feedback methods is available. In this study, two novel feedback variants using a bar or a tacho to visualize targets and deviation from targets were compared to a classic design using only numbers. Participants (6 female and 25 male trained to well-trained athletes) completed a protocol consisting of three heart rate-based tasks and one power-based task. The displays were compared with respect to their ability to guide athletes during their trials. Results showed lower root mean square error (RMSE) of the novel variants, but no significant effect of feedback variant on RMSE was found for both tasks (p > 0.05). However, when comparing the feedback variants on a person to person basis, significant differences were found for all investigated scenarios (p < 0.001). This leads to the conclusion that novel feedback variants can improve athletes’ ability to follow heart rate-based and power-based protocols, but even better results might be achieved by individualizing the feedback. Key points

• Novel visual feedback variants, – different from traditional number-based displays – might increase accuracy in testing, i.e. help athletes to reduce deviations from assigned targets (heart rate or power).
• Individual differences between athletes exist with regard to the best feed-back variant.
• Best results could be achieved by providing athletes with individualized feedback.

Key words: Feedback, cycling, power, heart rate, accuracy, PEGASOS     

Validity, Reliability, and Responsiveness of a Digital Version of the Visual Analog Scale

The design used in this study was a prospective cohort. Pain intensity levels recorded by the digital version of the visual analog scale (VAS-D) are easy to both score and share with other health care professionals. The purpose of the study was to examine the test-retest reliability, concurrent validity, and responsiveness of the VAS-D. Thirty-three people with upper extremity injuries reported pain intensity levels before and after performing four maximal grip contractions (pre- and postgripping). Our version of the VAS-D had high test-retest reliability (r = 0.96) and good concurrent validity (r = 0.84-0.97) with both the paper version of the VAS (VAS-P) and the verbal numerical rating scale (NRS-V). Responsiveness of the VAS-D was indicated by a significant increase in pain levels from pre- to postgripping. Similar responsiveness to that of the VAS-P and NRS-V was indicated by similar effect size coefficients and analysis of variance of pain change scores. In conclusion, the VAS-D is a reliable, valid, and responsive measure of pain intensity for people with upper extremity injuries. However, differences in accuracy (resolution) among the VAS-D, VAS-P, or NRS-V may render the three pain scales not fully compatible.

Level of Evidence

Not applicable.     

Usability and Reliability of the Edinburgh Visual Gait Score in Children with Spastic Cerebral Palsy Using Smartphone Slow-Motion Video Technology and a Motion Analysis Application: A Pilot Study

BackgroundThe Edinburgh Visual Gait Score (EVGS) is a comprehensive measure of gait abnormalities in children with cerebral palsy (CP) and has good psychometric properties. However, it is cumbersome to administer and requires multiple devices to record and measure its various components. We conducted this study to determine if a smartphone video protocol could be used to improve the usability and reliability of the EVGS for daily use in a clinic setting.MethodsWe used a handheld smartphone camera with slow-motion video technology and a motion analysis application to record and measure the EVGS of 30 ambulatory children with spastic CP. We tested the inter- and intra-rater reliability of various components of the EVGS between two observers.ResultsAverage age was 7 years 3 months (range 4–14 years). The mean (range) EVGS scores for the trunk, pelvis, hip, knee, ankle, and foot were 1.18 (0–3), 0.68 (0–3), 1.1 (0–4), 3.95 (1.5–7.5), 1.87 (0–4) and 4.13 (2–6.5) respectively. Total score was 12.92 (7–21.5). The mean (SD) scores for Gross Motor Function Classification System (GMFCS) levels II and III were 10.73 (3.86) and 14.96 (4.2) (p < 0.001). The intra-observer and inter-observer reliability using percentage of complete agreement was 65–98.3% and 61.7–92.5% respectively, with kappa values ranging from 0.15 to 0.87. Reliability was more for distal limb segments as compared to proximal segments.ConclusionWe have described a simple and reliable method for quantitative OGA of children with CP, using smartphone video technology and motion analysis application, which can be performed by every clinician in an office setting.Level of EvidenceLevel III.     

Exercise and Mechanical Loading Increase Periosteal Bone Formation and Whole Bone Strength in C57BL/6J Mice but Not in C3H/Hej Mice

To identify the genes, and the mechanisms that account for the 53% higher peak bone density in C3H/HeJ (C3H) mice compared with C57BL/6J (B6) mice, we are performing quantitative trait locus and phenotypic analyses. The phenotypic studies revealed differences in bone formation and resorption, and showed that hindlimb immobilization (by sciatic neurectomy) caused a greater increase in endosteal resorption in the tibiae of B6 compared with C3H mice. The current studies were intended to examine the hypothesis that the bones of C3H mice are less sensitive to mechanical loading than the bones of B6 mice. To increase mechanical loading, 9-week-old female B6 and C3H mice (n = 10–13 mice/group) were subjected to a jumping exercise (20 jumps/day, 5 days/week, to heights of 20–30 cm) for a total of 4 weeks. Control mice did not jump. Osteocalcin, alkaline phosphatase (ALP) activity, and IGF-I were measured in serum. The left tibiae were used for histomorphometry (ground cross-sections prepared at the tibio-fibular junction) and the right tibiae and femora were used for determinations of bone breaking strength (3-point bending). The results of these studies revealed (1) significant effects of both mouse strain (B6 and C3H) and the jumping exercise on tibial strength; (2) an exercise-dependent increase in serum IGF-I in C3H, but not B6 mice; and (3) no effects on serum ALP or osteocalcin. The histomorphometric analyses showed no effect of exercise on C3H tibiae, but significant exercise-dependent increases in total bone area, periosteal perimeter, periosteal mineral apposition rate (MAR), and periosteal bone formation (P < 0.02 for each) in B6 tibiae. There were no effects of exercise on periosteal resorption or any endosteal measurement in either C3H or B6 mice. Since the jumping exercise was designed to cause a two–three fold increase in muscular-skeletal loading at the tibio-fibular junction, and the calculated stress (g/mm²) at this sampling site was only 16% greater for B6 compared with C3H mice, we had anticipated that both strains of mice would show exercise-dependent increases in periosteal bone formation, with a greater response in the B6 mice. The lack of a response in the C3H tibiae demonstrates that the bones of C3H mice are less sensitive to mechanical loading (and unloading) than the bones of B6 mice. Received: 21 July 1999 / Accepted: 2 November 1999