Search results for "KNEE"
showing 10 items of 527 documents
Knee and ankle joint stiffness in sprint running.
2002
Stiffness has often been considered as a regulated property of the neuromuscular system. The purpose of this study was to examine the ankle and knee joint stiffness regulation during sprint running.Ten male sprinters ran at the constant relative speeds of 70, 80, 90, and 100% over a force platform, and ground reaction forces, kinematic, and EMG parameters were collected.The results indicated that with increasing running speed the average joint stiffness (change in joint moment divided by change in joint angle) was constant (7 N x m x deg(-1)) in the ankle joint and increased from 17 to 24 N x m x deg(-1) (P0.01) in the knee joint.The observed constant ankle joint stiffness may depend on (co…
Electromyographic and kinematic analysis of therapeutic knee exercises under water.
2001
Abstract Objective. This study aimed to evaluate muscle function and kinematics during commonly used knee rehabilitation exercises performed in water. Design. Maximal effort single extension and flexion trials in still water and repeated extension–flexion trials in flowing water in barefoot condition were analysed from 18 healthy participants (8 men, 10 women). Background. Despite the fact that water exercises are widely used, there are only few studies involving biomechanical and hydrodynamical analysis of aquatic exercises in rehabilitation. Methods. Electromyography of the quadriceps (vastus medialis, vastus lateralis) and hamstring muscles (biceps femoris, semitendinosus) and angular ve…
Neuromuscular function during therapeutic knee exercise under water and on dry land
2001
Abstract Poyhonen T, Keskinen KL, Kyrolainen H, Hautala A, Savolainen J, Malkia E. Neuromuscular function during therapeutic knee exercise under water and on dry land. Arch Phys Med Rehabil 2001;82:1446-52. Objectives: To compare muscle activity and resistive drag force during knee extension-flexion exercises while barefoot and while wearing a Hydro Boot (increased frontal area) both under water and on dry land. Design: Participants performed the exercises while seated on an elevator chair under water. Setting: A hydrotherapy pool. Participants: Eighteen healthy persons (10 women, 8 men). Interventions: Not applicable. Main Outcome Measures: Isokinetic and isometric forces were measured wit…
Neuromuscular Differences Between Endurance-Trained, Power-Trained, and Sedentary Subjects
2003
This study tested the hypothesis that neuromuscular characteristics of plantar flexor (PF) and knee extensor (KE) muscles explain differences of both performance in vertical jump and maximal voluntary isometric contraction (MVC) between endurance-trained (END, n = 9), power-trained (POW, n = 8), and sedentary subjects (SED, n = 8). Evoked twitch characteristics of PF and KE were measured. MVC, maximal voluntary activation (%VA) of KE, and performance in vertical jump were also measured. POW have higher maximal rate of twitch force development (MRFD) than SED and END for both PF (p < 0.05) and KE (p < 0.01); %VA and MVC were higher for POW and END than SED (p < 0.01). Higher performances wer…
Neuromuscular fatigue following constant versus variable-intensity endurance cycling in triathletes
2008
International audience; The aim of this study was to determine whether variable power cycling produced greater neuromuscular fatigue of knee extensor muscles than constant power cycling at the same mean power output. Eight male triathletes (age : 33 ± 5 yr, mass : 74 ± 4 kg, OV&2max : 62 ± 5 ml.kg-1.min-1, maximal aerobic power : 392 ± 17 W) performed two 30 min trials on a cycle ergometer in a random order. Cycling exercise was performed either at a constant power output (CP) corresponding to 75% of the maximal aerobic power (MAP) or a variable power output (VP) with alternating ± 15%, ± 5%, and ± 10% of 75% MAP approximately every 5 min. Maximal voluntary contraction (MVC) torque, maximal…
Therapeutic synergism between hyaluronic acid and dexamethasone in the intra-articular treatment of osteoarthritis of the knee: a preliminary open st…
1992
In vitro studies on the effects of dexamethasone on human synovial cells have shown that with high concentrations of the steroid in the culture medium cellular activity was completely blocked whereas with low concentrations (10(-6)M), cellular density decreased but there was an increase in the synthesis of RNA, DNA, protein and hyaluronic acid. These data, coupled with clinical experience of using intra-articular hyaluronic acid to treat patients with osteoarthritis of the knee, prompted the investigators to carry out an open, randomized study of the use of very small doses of dexamethasone in association with hyaluronic acid in 40 osteoarthritic patients. Twenty patients received a weekly …
Neural activation after maximal isometric contractions at different muscle lengths.
2006
DESBROSSES K., N. BABAULT, G. SCAGLIONI, J.-P. MEYER, and M. POUSSON. Neural Activation after Maximal Isometric Contractions at Different Muscle Lengths. Med. Sci. Sports Exerc., Vol. 38, No. 5, pp. 937–944, 2006. Purpose: To investigate i) whether neural activation dependence on muscle length is preserved with neuromuscular fatigue and ii) whether fatigue induced by a maximal isometric exercise is muscle length dependent. Methods: Twelve male subjects performed two fatiguing quadriceps muscle exercises: FS is the fatigue carried out at short muscle length (S) (S = 40- of knee flexion) and FL is the fatigue at long muscle length (L) (L = 100-). Before and after each fatiguing exercise (i.e.…
Plasma catecholamine responses to four resistance exercise tests in men and women
1999
The plasma adrenaline ([A]) and noradrenaline ([NA]) concentration responses of nine men and eight women were investigated in four resistance exercise tests (E80, E60, E40 and E20), in which the subjects had to perform a maximal number of bilateral knee extension-flexion movements at a given cycle pace of 0.5 Hz, but at different load levels (80%, 60%, 40% and 20% of 1 repetition maximum, respectively). The four test sessions were separated by a minimal interval of 3 rest days. The number of repetitions (Repmax), the total work (Wtot) done normalized for the lean body mass and the heart rate (HR) responses were similar in the two groups in each test. In addition, no differences were found b…
Osteochondritis dissecans of the lateral tibial condyle. Report of a new case and review of the literature.
1989
Osteochondritis dissecans (OD) of the lateral tibial condyle is a rare condition. A review of the literature revealed only nine cases in seven patients. We report about a new case. It is widely accepted that this form of OD originates from an accessory center of ossification. Our case supports this theory. Although comparative roentgenograms of the left knee, taken because of complaints in the right one, were interpreted to be normal, retrospective analysis clearly revealed the lateral intercondylar eminence of the left knee to have been irregular many years before the onset of symptoms. Association with a classical OD in the contralateral knee is striking in most of the reported cases.
CD3+ lymphocytosis in the peri-implant membrane of 222 loosened joint endoprostheses depends on the tribological pairing.
2017
Background and purpose — The most frequent cause of arthroplasty failure is aseptic loosening—often induced by particles. Abrasion material triggers inflammatory reactions with lymphocytic infiltration and the formation of synovial-like interface membranes (SLIM) in the bone–implant interface. We analyzed CD3 quantities in SLIM depending on articulating materials and possible influences of proven material allergies on CD3 quantities. Patients and methods — 222 SLIM probes were obtained from revision surgeries of loosened hip and knee arthroplasties. SLIM cases were categorized according to the SLIM-consensus classification and to the particle algorithm. The CD3 quantities were analyzed immu…