Potential loss of muscle function during dynamic actions caused by significantly decreased muscle strength in older women with hip osteoarthritis.

PURPOSE: The aim of the study was to analyze the results of the hip joint torques within the patients with osteoarthritis (OA). A total of 119 women were divided into 3 groups performing 3 dimensional strength tests. For the measurements a new apparatus was invented and used. Specially designed position was safety and comfortable during testing OA and elderly women. RESULTS: Significant differences (p≤0.05) in strength tests were found both between body side and muscle groups in most of the performed tests. The biggest unilateral deficit in OA group was found in muscles most important for gait and weight bearing − 0.55 for both flexors and extensors. Surprisingly no lateral difference was found for the hip joint adductors. Analysis of the correlation coefficient between the hip joint muscles proved that complex movements needed well-developed coordination between the muscle groups. The most important agonist muscle coordination occurs between hip extensors and abductors − 0.68 to 0.80. CONCLUSION: Unilateral hip OA affecting older women is directly responsible for significantly lower muscle strength when compared with both control groups. Lost of balance and coordination needed for dynamic actions like gait is caused by strength asymmetry of crucial hip muscles as well as near zero correlation between important agonist muscles.

The effectiveness of a pendulum swing for the development of leg strength and counter-movement jump performance.

Various training devices have been developed to facilitate 'plyometric' training, one such device being the 'pendulum swing'. To assess the effectiveness of the pendulum swing, the results of a 3 week training programme using a combination of pendulum swing and weight-training exercises were compared to those of a weight-training programme. Subjects were assigned to one of two groups (n = 9) for weight-training only or for combined pendulum and weight-training. Both groups performed the same number of exercise repetitions. Measurements of isometric knee and hip extension-flexion, 1-RM squat weight, maximum jump height and power for a counter-movement jump were taken pre-training, 2 days after the end of the programme and 2 weeks after the end of the programme. The data were analysed using two-way MANOVA and MANCOVA techniques. Both methods showed significant (P < 0.05) increases in knee and hip extension strength. Hip and knee flexion strength increased only for the weight-trained group. Counter-movement jump height increased for both groups (weight-trained, P < 0.05; combined, P < 0.01). Maximum power increased only for the combined group (P < 0.05). When the pre-training scores were used as a covariate, the weight-trained group showed a greater increase in hip flexion and extension strength and knee flexion strength than the combined training group (P < 0.05). The combined group showed the greatest increase in knee extensor strength. It is concluded that the pendulum system induces a training effect which could be used to supplement weight-training for improving vertical jump performance.

Investigation of an experimental weight-training programme.

The aim of this study was to compare the effects of conventional weight-training (control) with an experimental programme. The training programme consisted of 12 sessions, 3 a week for 4 weeks. The experimental group (n = 12) performed sets of forearm flexion with a barbell until a 20% decline in maximal force was noted. The controls (n = 11) trained according to established weight-training principles. Isometric tests were performed on both the right and left forearm flexors and during forearm flexion with a barbell: the tests were continued for a 3-week post-experimental period. The subjects were matched on all tests at the start of the experiment. Larger reductions in muscle torque within the training sessions were noted among the experimental subjects--19.8 +/- 2.0, 16.9 +/- 1.9 and 18.0 +/- 1.8% for right, left and combined elbow flexion respectively, compared to 11.8 +/- 2.7, 14.9 +/- 4.1 and 13.4 +/- 3.1% for the controls. The volume of training (number of lifts) was 30.4% higher for the experimental subjects. Muscle strength increased in both groups (P less than 0.05). The controls improved by 12.7 +/- 6.9, 24.9 +/- 22.1, 18.3 +/- 12.3 and 30.3 +/- 11.1% for right, left, combined isometric strength and the barbell test respectively. These did not differ significantly from the corresponding results for the experimental group--7.6 +/- 8.8, 17.0 +/- 12.4, 11.8 +/- 9.3 and 29.1 +/- 10.6% (P greater than 0.05). Neither the decrease in force during a single training session nor the volume of training were related to the training effect expressed as an increase in muscle force (P greater than 0.05). The effectiveness of the conventional programme in producing similar improvements in muscle strength to the experimental programme suggests that a high volume of training is unnecessary for strength gains.