Work‐Related Physical Activity Is Not Associated with Body Mass Index and Obesity

Objective: To analyze the association of work‐related physical activity (WRPA) and leisure‐time physical activity (LTPA) with body mass index (BMI) and obesity in the Spanish adult population aged 20 to 60 years. Research Methods and Procedures: The data were taken from the 1993 Spanish National Health Survey. We analyzed a sample of 12,044 men and women representative of the Spanish population aged 20 to 60 years. BMI and frequency of obesity (BMI ≥ 30 kg/m²) were obtained from self‐reported weight and height. Multiple linear regression and logistic regression models were constructed, adjusting for the main confounding factors. WRPA and LTPA were measured by two questions to classify subjects into four categories of physical activity. Results: Neither mean BMI nor percentage of obesity varied significantly (p > 0.05) by WRPA. Mean BMI was significantly higher (p < 0.01) in those who were inactive in their leisure time (25.90 kg/m² in men and 24.43 kg/m² in women) than in those who reported vigorous activity (24.42 kg/m² and 22.97 kg/m² in men and women, respectively). The odds ration (OR) for obesity decreased with increasing level of LTPA in both men (OR of 0.64 for vigorous activity) and women (OR = 0.68), showing a statistically significant dose‐response relation in both men (for linear trend, p = 0.0021) and women (p = 0.0245). Discussion: These results raise questions about the association between WRPA and obesity and suggest the need to reexamine models of the obesity epidemic that point to automation of the workplace as one of the major explanatory factors.     

Alta prevalencia de obesidad en una población laboral en España

Background and objectivesTo report the prevalence of obesity in a Spanish working population and its changes in recent years.Material and methodsData were collected from routine medical examinations performed on workers by a national mutual insurance society for occupational accidents and diseases (Ibermutuamur). A structured questionnaire was completed and physical examinations were performed. Overweight was defined as BMI ranging from 25 and 29.9, obesity as BMI of 30-39.9, and morbid obesity as BMI ≥ 40 kg/m².ResultsData from 1,336,055 medical examinations performed from May 2004 to November 2007 were collected. Prevalence rates in the population examined in 2004 (n = 230,684; 73% males; average age, 36.4 years) were: morbid obesity, 0.5% (0.6% males, 0.5% females); obesity, 14.5% (17.0% males, 7.7% females); overweight, 38.4% (44.8% males, 21.3% females). Prevalence rates of obesity and overweight were higher in blue-collar workers (16.4% and 40.5% respectively) as compared to white-collar workers (10.9% and 34.4% respectively). There was a progressive increase in prevalence of obesity during the 4-year study (2004-2007) in both males (17.0%, 17.6%, 17.9%, 18.2%) and females (7.6%, 8.0%, 8.4%, 8.7%).ConclusionsPrevalence of obesity and overweight in the Spanish working population is high, especially in male blue-collar workers, and is increasing. There is a need to promote early prevention programs and specific treatments for obesity.     

Evaluating the impact of a school-based health intervention using a randomized field experiment

We conduct an econometric evaluation of a health-promoting programme in primary and lower secondary schools in Denmark. The programme includes health-related measurements of the students, communication of knowledge about health, and support of health-promoting projects for students. Half of the schools in the fourth largest municipality in Denmark were randomly selected into a treatment group implementing the programme, while the remainder served as a control group. We estimate both OLS models using only post-intervention observations and difference in differences (DID) models using also pre-intervention observations. We estimate effects of the initiative on BMI, waist/height ratio, overweight and obesity for the entire sample and by gender and grade. We find no consistent effect of the programme. When we use the entire sample, no estimates are statistically significant at conventional levels, although the point estimates for the effect on BMI, indicating an average reduction in the range of 0.10–0.15 kg/m², are consistent with the results in a recent Cochrane review evaluating 55 studies of diet and exercise interventions targeting children; and DID estimates which are marginally significant (at the 10% level) indicate that the intervention reduces the risk of obesity by 1% point. Running separate estimations by gender and grade we find a few statistically significant estimates: OLS estimates indicate that the intervention reduces BMI in females in grade 5 by 0.39 kg/m² and reduces the risk of obesity in females in grade 9 by 2.6% points; DID estimates indicate an increase in waist for females in preschool class by 1.2 cm and an increase in the risk of obesity in grade 9 males by 4% points. However, if we corrected for multiple hypotheses testing these estimates would be insignificant. There is no statistically significant correlation between participation in the programme and the number of other health-promoting projects at the schools.     

The relationship between external knee moments and muscle co-activation in subjects with medial knee osteoarthritis

PurposeExternal knee moments are reliable to measure knee load but it does not take into account muscle activity. Considering that muscle co-activation increases compressive forces at the knee joint, identifying relationships between muscle co-activations and knee joint load would complement the investigation of the knee loading in subjects with knee osteoarthritis. The purpose of this study was to identify relationships between muscle co-activation and external knee moments during walking in subjects with medial knee osteoarthritis.Methods19 controls (11 males, aged 56.6 ± 5, and BMI 25.2 ± 3.3) and 25 subjects with medial knee osteoarthritis (12 males, aged 57.3 ± 5.3, and BMI 28.2 ± 4) were included in this study. Knee adduction and flexion moments, and co-activation (ratios and sums of quadriceps, hamstring, and gastrocnemius) were assessed during walking and compared between groups. The relationship between knee moments and co-activation was investigated in both groups.FindingsSubjects with knee osteoarthritis presented a moderate and strong correlation between co-activation (ratios and sums) and knee moments.InterpretationMuscle co-activation should be used to measure the contribution of quadriceps, hamstring, and gastrocnemius on knee loading. This information would cooperate to develop a more comprehensive approach of knee loading in this population.     

Effectiveness of weight loss intervention in highly-motivated people

A variety of approaches have been implemented to address the rising obesity epidemic, with limited success. I consider the success of weight loss efforts among a group of highly motivated people: those required to lose weight in order to qualify for a life-saving kidney transplantation. Out of 246 transplantation centers, I identified 156 (63%) with explicit body mass index (BMI) requirements for transplantation, ranging from 30 to 50 kg/m². Using the United States national registry of transplant candidates, I examine outcomes for 29,608 obese deceased-donor transplant recipients between 1990 and 2010. I use value-added models to deal with potential endogeneity of center choice, in addition to correcting for sample selection bias arising from focusing on transplant recipients. Outcome variables measure BMI level and weight change (in BMI) between initial listing and transplantation. I hypothesize that those requiring weight loss to qualify for kidney transplantation will be most likely to lose weight. I find that the probability of severe and morbid obesity (BMI ≥ 35 kg/m²) decreases by 4 percentage points and the probability of patients achieving any weight loss increases by 22 percentage points at centers with explicit BMI eligibility criteria. Patients are also 13 percentage points more likely to accomplish clinically relevant weight loss of at least 5% of baseline BMI by transplantation at these centers. Nonetheless, I estimate an average decrease in BMI of only 1.7 kg/m² for those registered at centers with BMI requirements. Further analyses suggest stronger intervention effects for patients whose BMI at listing exceeds thresholds as the distance from their BMI to the thresholds increases. Even under circumstances with great potential returns for weight loss, transplant candidates exhibit modest weight-loss. This suggests that, even in high-stakes environments, weight loss remains a challenge for the obese, and altering individual incentives may not be sufficient.     

Obesity,physical activity and cancer risks: Results from the Cancer,Lifestyle and Evaluation of Risk Study (CLEAR)

IntroductionPhysical activity (PA) has been associated with lower risk of cardiovascular diseases, but the evidence linking PA with lower cancer risk is inconclusive. We examined the independent and interactive effects of PA and obesity using body mass index (BMI) as a proxy for obesity, on the risk of developing prostate (PC), postmenopausal breast (BC), colorectal (CRC), ovarian (OC) and uterine (UC) cancers.MethodsWe estimated odds ratios (OR) and 95% confidence intervals (CI), adjusting for cancer specific confounders, in 6831 self-reported cancer cases and 1992 self-reported cancer-free controls from the Cancer Lifestyle and Evaluation of Risk Study, using unconditional logistic regression.ResultsFor women, BMI was positively associated with UC risk; specifically, obese women (BMI ≥30 kg/m²) had nearly twice the risk of developing UC compared to women with healthy-BMI-range (<25 kg/m²) (OR = 1.99;CI:1.31–3.03). For men, BMI was also positively associated with the risk of developing any cancer type, CRC and PC. In particular, obese men had 37% (OR = 1.37;CI:1.11–1.70), 113% (OR = 2.13;CI:1.55–2.91) and 51% (OR = 1.51;CI:1.17-1.94) higher risks of developing any cancer, CRC and PC respectively, when compared to men with healthy-BMI-range (BMI<25 kg/m²).Among women, PA was inversely associated with the risks of CRC, UC and BC. In particular, the highest level of PA (versus nil activity) was associated with reduced risks of CRC (OR = 0.60;CI:0.44–0.84) and UC (OR = 0.47;CI:0.27–0.80). Reduced risks of BC were associated with low (OR = 0.66;CI:0.51–0.86) and moderate (OR = 0.72;CI:0.57–0.91) levels of PA. There was no association between PA levels and cancer risks for men.We found no evidence of an interaction between BMI and PA in the CLEAR study.ConclusionThese findings suggest that PA and obesity are independent cancer risk factors.     

Characteristic gait patterns in older adults with obesity—Results from the Baltimore Longitudinal Study of Aging

Obesity in older adults is a growing public health problem. Excess weight causes biomechanical burden to lower extremity joints and contribute to joint pathology. The aim of this study was to identify specific characteristics of gait associated with body mass index (BMI). Preferred and maximum speed walking and related gait characteristics were examined in 164 (50–84 years) participants from Baltimore Longitudinal Study of Aging (BLSA) able to walk unassisted. Participants were divided into three groups based on their BMI: normal weight (19≤BMI<25 kg/m²), overweight (25≤BMI<30 kg/m²) and obese (BMI 30≤BMI<40 kg/m²). Total ankle generative mechanical work expenditure (MWE) in the anterior–posterior (AP) plane was progressively and significantly lower with increase in BMI for both preferred (p=0.026) and maximum speed walking (p<0.001). In the medial–lateral (ML) plane, total knee generative MWE was higher in obese participants in the preferred speed task (p=0.002), and total hip absorptive MWE was higher in obese in both preferred speed (p<0.001) and maximum speed (p=0.002) walking task compared to the normal weight participants. Older adults with obesity show spatiotemporal gait patterns that may help in reducing contact impacts. In addition, in obese persons mechanical energy usages tend to be lower in the AP plane and higher in the ML plane. Since forward progression forces are mainly implicated in normal walking, this pattern found in obese participants is suggestive of lower energetic efficiency.     

Delayed onset of electromyographic activity of the vastus medialis relative to the vastus lateralis may be related to physical activity levels in females with patellofemoral pain

The aims of this study were to examine group differences in muscle activation onset of the vastus medialis (VM) in relation to the vastus lateralis (VL) and pain level during stair ascent in females with patellofemoral pain (PFP) who maintain high and moderate levels of physical activity; to determine the association between physical activity level and muscle activation onset. Forty-three females with PFP and thirty-eight pain-free females were recruited and divided into four groups based on their level of physical activity: females with PFP (n = 26) and pain-free females (n = 26) who practiced a moderate level of physical activity and females with PFP (n = 17) and pain-free females (n = 12) who practiced an intense amount of physical activity. Participants were asked to ascend a seven-step staircase and the VM and VL activation onset was determined. Females with PFP who practiced high level of physical activity demonstrated delayed onset of VM (4.06 ms) compared to healthy females (−14.4 ms). Conversely, females with PFP who practiced moderate level of physical activity did not present VM delay (−2.48 ms) in comparison to healthy females (−9.89 ms). Furthermore, physical activity significantly correlated to the muscle activation onset difference (p = 0.005; R = 0.60). These findings may explain why controversial results regarding VM and VL muscle activation onset have been found.     

The biological standard of living in Suriname,c. 1870–1975

The physical stature of Surinamese soldiers is estimated to have increased by more than 3 cm between 1870 and 1909. In the subsequent four decades, the increase in adult male and female height amounted to 0.3–0.5 cm and 0.9–1.0 cm per decade, respectively. This increase in height continued and accelerated during the second half of the twentieth century. Height increase among African and Hindustani Surinamese males and females was similar. Height differences between African and Hindustani Surinamese were therefore fairly constant over time, at 4–5 cm. Other indicators of nutritional and health status, such as infant mortality, showed continuous improvement, whereas per capita calorie and protein availability improved in the twentieth century.     

Body mass index and screening for colorectal cancer: gender and attitudinal factors

Background: Overweight/obese women and men are at increased risk for colorectal cancer (CRC) incidence and mortality. Research examining body mass index (BMI) and CRC screening has had mixed results. A clearer understanding of the extent to which high-BMI subgroups are screened for CRC is needed to inform planning for CRC screening promotions targeting BMI. Methods: Data were obtained from a random, population-based sample of women and men at average-risk for CRC (aged 50–75 years) during 2004 (n = 1098). Multiple logistic regression analyses were conducted to evaluate whether BMI category was significantly associated with the probability of reporting recent CRC screening and with the probability of agreeing with statements denoting attitudes/perceptions about CRC and screening. Attitudes/perceptions about CRC and screening were evaluated as potential mediators and moderators of the association between BMI category and CRC screening. Results: After controlling for characteristics associated with CRC screening, overweight and obese women were each 40% less likely to have CRC screening than women with normal-BMI (OR = 0.6, 95% CI:0.4–0.9 and OR = 0.6, 95% CI:0.3–0.9). BMI category was unrelated to screening among men. Obese women (but not men) were less aware than normal-BMI women that obesity increased risk for CRC (OR = 0.5, 95% CI:0.3–0.9) and less worried about CRC (OR = 0.5, 95% CI:0.3–0.8). However, findings suggest that attitudes/perceptions about CRC and screening did not mediate or moderate the association between BMI category and CRC screening. Conclusion: Overweight/obese women are at increased risk for CRC because of their greater BMI and their propensity not to screen for CRC. Study findings suggest that potentially modifiable perceptions, e.g., lack of awareness of risk for CRC and less worry about CRC, in this subgroup may not explain the relationship between BMI category and reduced screening.     

Relationships between neighborhoods, physical activity, and obesity: a multilevel analysis of a large canadian city

In Canada, there is limited research examining the associations between objectively measured neighborhood environments and physical activity (PA) and obesity. The purpose of this study was to determine the relationships between variables from built and social environments and PA and overweight/obesity across 86 Ottawa, Canada neighborhoods. Individual-level data including self-reported leisure-time PA (LTPA), height, and weight were examined in a sample of 4,727 adults from four combined cycles (years 2001/03/05/07) of the Canadian Community Health Survey (CCHS). Data on neighborhood characteristics were obtained from the Ottawa Neighbourhood Study (ONS); a large study of neighborhoods and health in Ottawa, Canada. Binomial multivariate multilevel models were used to examine the relationships between environmental and individual variables with LTPA and overweight/obesity using survey weights in men and women separately. Within the sample, ~75% of the adults were inactive (<3.0 kcal/kg/day) while half were overweight/obese. Results of the multilevel models suggested that for females greater park area was associated with increased odds of LTPA and overweight/obesity. Greater neighborhood density of convenience stores and fast food outlets were associated with increased odds of females being overweight/obese. Higher crime rates were associated with greater odds of LTPA in males, and lower odds of male and female overweight/obesity. Season was significantly associated with PA in men and women; the odds of LTPA in winter months were half that of summer months. Findings revealed that park area, crime rates, and neighborhood food outlets may have different roles with LTPA and overweight/obesity in men and women and future prospective studies are needed.     

Associations between household income,height, and BMI in contemporary US schoolchildren

This paper evaluates the association between income and physical development in a nationally representative sample of contemporary US schoolchildren followed from kindergarten to eighth grade (average ages of 6–14). A generalized linear mixed modeling framework is used to evaluate height and body mass index (BMI) as both levels and annualized growth in a pooled sample. Contemporary US schoolchildren show income variation in height that is significant but modest at around .1 cm (in kindergarten) to .4 cm (eighth grade) increases per doubling of income. An exception is found for Hispanic children who show faster height velocity associated with higher income through childhood yielding a 1.0 cm increase per doubling of income by the eighth grade. All groups except black males show a negative relationship between income and BMI that becomes stronger with age with an average .8 kg/m² lower BMI per doubling of income by the eighth grade. These results are robust to the inclusion of baseline anthropometric controls. The analysis suggests that higher-income US schoolchildren enter mid-adolescence as taller but with lower proportional body mass relative to their lower-income counterparts.     

In urban South Africa, 16 year old adolescents experience greater health equality than children

Despite the strongly established link between socio-economic status (SES) and health across most stages of the life-course, the evidence for a socio-economic gradient in adolescent health outcomes is less consistent. This paper examines associations between household, school, and neighbourhood SES measures with body composition outcomes in 16 year old South African Black urban adolescents from the 1990 born Birth to Twenty (Bt20) cohort. Multivariable regression analyses were applied to data from a sub-sample of the Bt20 cohort (n = 346, 53% male) with measures taken at birth and 16 years of age to establish socio-economic, biological, and demographic predictors of fat mass, lean mass, and body mass index (BMI). Results were compared with earlier published evidence of health inequality at ages 9–10 years in Bt20. Consistent predictors of higher fat mass and BMI in fully adjusted models were being female, born post term, having a mother with post secondary school education, and having an obese mother. Most measures of SES were only weakly associated with body composition, with an inconsistent direction of association. This is in contrast to earlier findings with Bt20 9–10 year olds where SES inequalities in body composition were observed. Findings suggest targeting obesity interventions at females in households where a mother has a high BMI.     

Surface electromyography reveals males have a slower patellar reflex than females

In humans the cross sectional area of spinal motor neurons at L3 is larger in males than in females. Since these contribute to the control of the quadriceps femoris muscle group and are involved in the patellar reflex (PR), gender differences in the PR are expected. We have investigated this possibility using a group of 28 young subjects (14 male and 14 female) aged 20–22 years. The PR was quantified by the muscle compound action potential (MCAP) from the surface electromyogram (sEMG) of the vastus lateralis muscle. We found that the PR latency in females (17 ± 0.19 ms), was significantly (p < 0.001) faster than in males (21 ± 0.37 ms). This 4 ms difference in latency could not be ascribed to differences in stature or thigh length. In conclusion, for the age range tested females posses a significantly faster patellar reflex than males. We suggest that the slower PR latency of male subjects may arise in part from their larger α-motorneurons: such that longer integration times are required for the summation of postsynaptic excitation to be sufficient to excite α-motorneurons.     

Gender-dependent impacts of body mass index and moderate alcohol consumption on serum uric acid—an index of oxidant stress status?

Uric acid seems to be causally involved in a variety of medical disorders involving oxidative stress. Although alcohol abuse and obesity are known to increase serum uric acid, the interactions between moderate drinking, adiposity, and uric acid metabolism have remained poorly understood. We examined serum uric acid concentrations from 2062 apparently healthy volunteers (970 men, 1092 women) reporting either no alcohol (abstainers) or < 40 g of ethanol consumption per day (moderate drinkers). The study population was further classified according to BMI as follows: < 19 (underweight), 19–25 (normal weight), 25–30 (overweight), and > 30 (obese). Serum uric acid concentrations in male moderate drinkers were significantly higher, and in females they were lower, than in the corresponding groups of abstainers. In the BMI-based subgroups, the highest concentrations were found in those who were overweight or obese. Significant two-factor interactions occurred between gender and drinking status (p < 0.001) and between gender and BMI (p < 0.02). Serum uric acid also correlated with indices of hepatocellular health (GGT, ALT, AST). The data indicate distinct gender-dependent impacts of alcohol consumption and BMI on serum uric acid. These findings should be applicable to the assessment of oxidative stress status and associated morbidity in alcohol consumers and individuals with excess body weight.     

Low-grade inflammation markers in children and adolescents: Influence of anthropometric characteristics and CRP and IL6 polymorphisms

Overweight and obesity are associated with chronic and subclinical inflammation due to an imbalance of inflammatory mediators. However, the association with gene polymorphism has been rarely studied in children. The aim of this study was to determine if serum concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) are related to the IL6 rs1800795, IL6 rs2069845 and CRP rs1205 polymorphisms (SNPs) according to body mass index (BMI) in a sample of children and adolescents. A cross-sectional study in 470 students between 7 and 17 years of age of anthropometric characteristics, high sensitivity-CRP (Hs-CRP) and IL-6 levels and three SNPs genotyped. The prevalence ratio of hs-CRP > 3 mg/L in obese individuals was 4.15 (CI 2.43–7.06; p = 0.01), and it was 1.91 (CI 1.03–3.55; p = 0.03) in overweight individuals and 1.74 (CI 1.05–2.88 p = 0.03) in females. Individuals with waist circumference (WC) and body fat percentage (BF%) alterations showed elevated levels of hs-CRP (p = 4.3 × 10⁻⁵ and p = 5.3 × 10⁻⁶). The combination of any two anthropometric measurement increases CRP levels, especially combinations with obesity body mass index (BMI): BMI + WC and BMI + BF%. Among the overweight/obesity group, T allele carriers of CRP rs1205 showed lower levels of hs-CRP (0.5, IQR = 0.3–1.8 mg/L) than CC homozygotes (1.5, IQR = 0.4–3.4 mg/L, p = 0.018). Additionally, considering subjects with two or three anthropometric alterations for CRP rs1205: rs1205 T allele carriers had lower levels of hs-CRP (0.7, IQR = 0.3–2.7 mg/L) than CC homozygotes (1.2, IQR = 0.5–3.5 mg/L, p = 0.02). In conclusion, carriers of the rs1205/T allele with higher BMIs had lower levels of hs-CRP. Schoolchildren who were overweight/obese had higher levels of CRP and IL-6, whereas individuals with WC and BF% alterations had higher levels of CRP.     

Temperature-dependent development of overwintering Sericinus montela Gray (Lepidoptera: Papilionidae) pupae and its validation

The developmental time and survival of overwintering Sericinus montela Gray pupae were studied at four constant temperatures (15.0, 20.0, 25.0, and 30.0 °C), 40 ± 10% relative humidity, and 10:14 h light:dark cycle. The developmental time of both sexes decreased with increasing temperature between 15.0 °C (70.18 days for females and 55.28 days for males) and 30.0 °C (19.60 days for females and 13.78 days for males). The development periods of females were longer than those of males at each constant temperature. The relationship between the developmental rate and temperature was fitted by a linear model and a nonlinear developmental rate model (Lactin 1). The mortality of overwintered S. montela pupae was lowest at 25.0 °C (16.7%) and highest at 15.0 °C (36.7%). The lower developmental thresholds were 12.38 and 12.16 °C for females and males, respectively. The distribution of development completion for females and males was described by the two-parameter Weibull distribution equation (r² = 0.87 for females and r² = 0.94 for males). The date for the cumulative 50% adult emergence was within one or two days of that predicted using the Lactin 1 model. The temperature-dependent developmental model for S. montela could be applied to predict the timing of spring emergence in different geographical locations and will be helpful in developing a full-cycle phenology model for S. montela.     

Unbiased sex-specific survival in Alpine chamois

Many polygynous ungulates show higher mortality of males than of females, because of the intense male–male competition during the rut and the costs associated with the development of sexual-size dimorphism. In the weakly dimorphic Alpine chamois Rupicapra rupicapra the occurrence of differential sex-specific survival strategies is controversial. To date, only two studies investigated the survivorship of males and females in this species, producing conflicting results: these works, based on the use of life tables, require confirmation from researches carried out on living populations. We assessed the survival pattern of a protected Alpine chamois population in the Swiss National Park, where 116 individuals were marked and monitored over 13 years (1996–2008). We tested for sex-, age- and year-dependence of survival by means of capture-mark-resight models. Resighting probabilities were sex-dependent, and survival rates were time-dependent. Females had higher resighting probabilities (0.84) than males (0.74). All over the time periods, sex had a weak influence on survival probability (males = 0.91; females = 0.92) and survival rates remained surprisingly high until late age (1 year = 0.90; 2–7 years = 0.91; 8+ years = 0.92). The growing evidence for a high adult survival and a weak differential mortality of the two sexes, together with the highly seasonal sexual-size dimorphism observed for Alpine chamois, might indicate the occurrence of a unique conservative survival strategy in both sexes and a low-risk mating strategy by males.     

Validity and reliability of isometric,isokinetic and isoinertial modalities for the assessment of quadriceps muscle strength in patients with total knee arthroplasty

Reliability of isometric, isokinetic and isoinertial modalities for quadriceps strength evaluation, and the relation between quadriceps strength and physical function was investigated in 29 total knee arthroplasty (TKA) patients, with an average age of 63 years. Isometric maximal voluntary contraction torque, isokinetic peak torque, and isoinertial one-repetition maximum load of the involved and uninvolved quadriceps were evaluated as well as objective (walking parameters) and subjective physical function (WOMAC). Reliability was good and comparable for the isometric, isokinetic, and isoinertial strength outcomes on both sides (intraclass correlation coefficient range: 0.947–0.966; standard error of measurement range: 5.1–9.3%). Involved quadriceps strength was significantly correlated to walking speed (r range: 0.641–0.710), step length (r range: 0.685–0.820) and WOMAC function (r range: 0.575–0.663), independent from the modality (P < 0.05). Uninvolved quadriceps strength was also significantly correlated to walking speed (r range: 0.413–0.539), step length (r range: 0.514–0.608) and WOMAC function (r range: 0.374–0.554) (P < 0.05), except for WOMAC function/isokinetic peak torque (P > 0.05). In conclusion, isometric, isokinetic, and isoinertial modalities ensure valid and reliable assessment of quadriceps muscle strength in TKA patients.