The purpose of this study was to assess the effect of whole body vibration (WBV) exercise on muscle strength and proprioception in female patients with osteoarthritis in the knee (knee-OA). A single blinded, randomised, controlled trial was performed in an outpatient clinic on 52 female patients diagnosed with knee-OA (mean age 60.4 years+/-9.6). They were randomly assigned to one of 3 groups: 1. WBV-exercise on a stable platform (VibM; n=17 (mean age, 61.5+/-9.2)), WBV-exercise on a balance board (VibF; n=18 (mean age, 58.7+/-11.0)), or control group (Con; n=18 (mean age, 61.1+/-8.5)). The WBV groups trained twice a week for 8 weeks, with a progressively increasing intensity. The WBV groups performed unloaded static WBV exercise. The following were measured: knee muscle strength (extension/flexion) and proprioception (threshold for detection of passive movement (TDPM)). Self-reported disease status was measured using WOMAC. It was found that muscle strength increased significantly (p<0.001) in VibM compared to Con. Isometric knee-extension significantly increased (p=0.021) in VibM compared to Con. TDPM was significantly improved (p=0.033) in VibF compared to Con, while there was a tendency (p=0.051) for VibM to perform better compared to Con. There were no effects in the self-reported disease status measures. This study showed that the WBV-exercise regime on a stable platform (VibM) yielded increased muscle strength, while the WBV-exercise on a balance board (VibF) showed improved TDPM. The WBV-exercise is a time-saving and safe method for rehabilitation of women with knee-OA.

OBJECTIVE: The purpose of this study was to investigate whether the knee joint dynamics during a forward lunge could be modulated by experimentally induced vastus medialis pain in healthy subjects.

DESIGN: Randomised cross-over study.

SETTING: Biomechanical movement laboratory.

PARTICIPANTS: 20 healthy subjects were included. One subject was excluded during data collection.

INTERVENTION: The subjects performed forward lunges before, during and 20 minutes after induction of experimental quadriceps muscle pain. Muscle pain was induced using hypertonic saline (5.8%) injected intramuscularly. Isotonic saline (0.9%) was used as control.

MAIN OUTCOME MEASUREMENTS: Three-dimensional movement analyses were performed and inverse dynamics were used to calculate joint kinematics and kinetics for ankle, knee and hip joints. Electromyographic (EMG) signals of the hamstrings and quadriceps muscles were recorded.

RESULTS: During and after pain, significant decreases in knee joint dynamics and EMG recordings were observed.

CONCLUSION: The study shows that local pain in the quadriceps is capable of modulating movements with high knee joint dynamics. The results may have implications in the management of muscle pain and prevention of injuries during activities involving the knee joint.

Most non-inflammatory musculoskeletal diseases are more common in women than in men. Fibromyalgia is characterised by chronic generalised muscle pain. The male:female ratio is 1:9. Interacting factors including genetic, hormonal, environmental and behavioural elements may cause this condition, and there are possibly subgroups of which one has shown to be treatable. A different pathogenetic appearance in the two sexes may also be present. The gender difference may partly be explained by the fact that pressure pain test in tender points forms part of the diagnosis. This may leave some male fibromyalgia patients unrecognized.

The forward lunge movement may be used as a functional performance test of anterior cruciate ligament (ACL) deficient and reconstructed subjects. The purposes were 1) to determine the test-retest reliability of a forward lunge in healthy subjects and 2) to determine the required numbers of repetitions necessary to yield satisfactory reliability. Nineteen healthy subjects performed four trials of a forward lunge on two different days. The movement time, impulses of the ground reaction forces (IFz, IFy), knee joint kinematics and dynamics during the forward lunge were calculated. The relative reliability was determined by calculation of Intraclass Correlation Coefficients (ICC). The IFz, IFy and the positive work of the knee extensors showed excellent reliability (ICC >0.75). All other variables demonstrated acceptable reliability (0.4>ICC<0.75). The relative reliability increased when more than a single forward lunge was used. In conclusion, the reliability was acceptable. It is recommended to represent the biomechanical variables as an average of at least three trials of the forward lunge.

Udgivelsesdato: 2009-Jun