The present study aimed to compare quadriceps femoris muscle strength and fatigue between obese (grade II and III) and nonobese adults. Ten obese (mean age: 25 years; mean BMI: 41 kg/m(2)) and ten lean (mean age: 27 years; mean BMI: 23 kg/m(2)) men were tested. Quadriceps muscle fatigue was quantified as the (percent) torque loss during a voluntary isokinetic (50 maximal contractions at 180 degrees /s) and an electrostimulated (40 Hz) isometric protocol (5 min, 10% of the maximal torque). Maximal voluntary isometric and isokinetic torque and power were also measured. Voluntary torque loss was significantly higher (P < 0.05) in obese (-63.5%) than in lean subjects (-50.6%). Stimulated torque decreased significantly (P < 0.05) but equally in the two subject groups. Obese subjects displayed higher absolute (+20%; P < 0.01) but lower relative (i.e., normalized to body mass) (-32%; P < 0.001) muscle torque and power than their lean counterparts. Obese individuals demonstrated lower fatigue resistance during voluntary but not during stimulated knee extensions compared to their nonobese counterparts. Peripheral mechanisms of muscle fatigue -- at least those associated to the present stimulated test -- were not influenced by obesity. The observed quadriceps muscle function impairments (voluntary fatigue and relative strength) probably contribute to the reduced functional capacity of obese subjects during daily living activities.

The majority of patients returned to sports and recreational activity after unicompartmental knee arthroplasty. However, the numbers of different disciplines patients were engaged in decreased as well as the extent of activities. The activities in which most patients participated were primarily low- or midimpact. The patients scored higher on the SF-36 than age-related norms, which might be due to the patient-selection process for unicompartmental knee arthroplasty and geographical differences.

IntroductionPatient's expectations are variably reported to influence self-rated outcome and satisfaction after medical treatment; this prospective study examined which of the following was the most important unique determinant of global outcome/satisfaction after total knee arthroplasty (TKA): baseline expectations; fulfilment of expectations; or current symptoms and function.MethodsOne hundred and twelve patients with osteoarthritis of the knee (age, 67 ± 9 years) completed a questionnaire about their expectations regarding months until full recovery, pain, and limitations in everyday activities after TKA surgery. Two years postoperatively, they were asked what the reality was for each of these domains, and rated the global outcome and satisfaction with surgery. Multivariable regression analyses using forward conditional selection of variables (and controlling for age, gender, other joint problems) identified the most significant determinants of outcome.ResultsPatients significantly underestimated the time for full recovery (expected 4.7 ± 2.8 months, recalled actual time, 6.1 ± 3.7 months; P = 0.005). They were also overly optimistic about the likelihood of being pain-free (85% expected it, 43% were; P < 0.05) and of not being limited in usual activities (52% expected it, 20% were; P < 0.05). Global outcomes were 46.2% excellent, 41.3% good, 10.6% fair and 1.9% poor. In multivariable regression, expectations did not make a significant unique contribution to explaining the variance in outcome/satisfaction; together with other joint problems, knee pain and function at 2 years postoperation predicted global outcome, and knee pain at 2 years predicted satisfaction.ConclusionsIn this group, preoperative expectations of TKA surgery were overly optimistic. The routine analysis of patient-orientated outcomes in practice should assist the surgeon to convey more realistic expectations to the patient during the preoperative consultation. In multivariable regression, expectations did not predict global outcome/satisfaction; the most important determinants were other joint problems and the patient's pain and functional status 2 years postoperatively.

The aim of this study was to evaluate the reliability of isokinetic and isometric assessments of the knee extensor and the flexor muscle function using the Con-Trex isokinetic dynamometer. Thirty healthy subjects (15 males, 15 females) were tested and retested 7 days later for maximal strength (isokinetic peak torque, work, power and angle of peak torque as well as isometric maximal voluntary contraction torque and rate of torque development) and fatigue (per cent loss and linear slope of torque and work across a series of 20 contractions). For both the knee extensor and the flexor muscle groups, all strength data - except angle of peak torque - demonstrated moderate-to-high reliability, with intraclass correlation coefficients (ICC) higher than 0.86. The highest reliability was observed for concentric peak torque of the knee extensor muscles (ICC = 0.99). Test-retest reliability of fatigue variables was moderate for the knee extensor (ICC range 0.84-0.89) and insufficient-to-moderate for the knee flexor muscles (ICC range 0.78-0.81). The more reliable index of muscle fatigue was the linear slope of the decline in work output. These findings establish the reliability of isokinetic and isometric measurements using the Con-Trex machine.

The present study reports for the first time on the detailed sports activity and activity extent after hip resurfacing arthroplasty. Our patients could return to a high level of sports participation after surgery. Age-related differences were found that have not yet been published. Nevertheless, further follow-up is necessary to assess the influence of high-level activity on loosening and revision rates after hip resurfacing arthroplasty.