Peak Torque Of Quadriceps Muscle Research Articles

Motor-based priming: isokinetic outcomes of aerobic exercise in children with spastic diplegia

IntroductionPriming is a behavioural change generated by preceding stimuli. Priming physical activities with aerobic exercise could improve performance and function. The study aimed to investigate the effect of aerobic exercise before a rehabilitation program on quadriceps peak torque in children with cerebral palsy of spastic diplegia.MethodsOverall, 32 patients participated in this study; they were randomly assigned to 2 groups. Patients in the control group (A) engaged in a selected physical therapy program, while those in the experimental group (B) performed aerobic exercise by using a bicycle ergometer followed by application of the same selected physical therapy program as received by group A. The treatment programs were conducted 3 times per week for 12 successive weeks. Measurements obtained included concentric peak torque of quadriceps muscle at 30° as well as 90°. These measures were recorded 2 times: before and after the application of the treatment program.ResultsThere were statistically significant differences when comparing pre- and post-treatment mean values in each group. Also, there was a significant difference in favour of group B with regard to post-treatment mean values.ConclusionsIn accordance with the applied procedures, aerobic exercise is effective in improving quadriceps peak torque in children with cerebral palsy of spastic diplegia when applied before a physical therapy rehabilitation program.

Quadriceps strengthening exercises may not change pain and function in knee osteoarthritis

It is believed that Quadriceps strength training may reduce pain and improve functional activity in patients with knee osteoarthritis (OA). This improvement is generally attributed to an increase in quadriceps strength. This study investigated whether quadriceps muscle strength increases with decreasing pain, improving functional activity in knee OA. Twenty-four patients with knee OA participated in an 8-week treatment protocol including traditional physical therapy and strength training 3 sessions per week. Measurements were conducted before and after the intervention and included the peak torque of quadriceps muscle, pain by visual analogue scale (VAS), short Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and functional activity by the 2 minute walking test (2MWT) and time up & go test (TUGT). After the intervention, analysis of data illustrated that changes in quadriceps muscle strength correlated with changes in VAS (r2 = 0.310, p = 0.005), WOMAC (r2 < 0.278, p < 0.008) and 2MWT (r2 < 0.275, p < 0.009) significantly, although the correlation slope was negligible. No correlation was found between muscle strength and TUGT. However, the strength training significantly improved quadriceps muscle strength (p = 0.013), pain and functional activity (p = 0.000). This study showed that reduction in pain and improvement in functional activity occurs independently from an increase in quadriceps muscle strength in knee OA. It seems that increased quadriceps muscle strength may not be a cause of improvement in pain and functional activity in knee OA.

Kilohertz and Low-Frequency Electrical Stimulation With the Same Pulse Duration Have Similar Efficiency for Inducing Isometric Knee Extension Torque and Discomfort.

To test the hypotheses that, as compared with pulsed current with the same pulse duration, kilohertz frequency alternating current would not differ in terms of evoked-torque production and perceived discomfort, and as a result, it would show the same current efficiency. A repeated-measures design with 4 stimuli presented in random order was used to test 25 women: (1) 500-microsecond pulse duration, (2) 250-microsecond pulse duration, (3) 500-microsecond pulse duration and low carrier frequency (1 kHz), (4) 250-microsecond pulse duration and high carrier frequency (4 kHz). Isometric peak torque of quadriceps muscle was measured using an isokinetic dynamometer. Discomfort was measured using a visual analog scale. Currents with long pulse durations induced approximately 21% higher evoked torque than short pulse durations. In addition, currents with 500 microseconds delivered greater amounts of charge than stimulation patterns using 250-microsecond pulse durations (P < 0.05). All currents presented similar discomfort. There was no difference on stimulation efficiency with the same pulse duration. Both kilohertz frequency alternating current and pulsed current, with the same pulse duration, have similar efficiency for inducing isometric knee extension torque and discomfort. However, neuromuscular electrical stimulation (NMES) with longer pulse duration induces higher NMES-evoked torque, regardless of the carrier frequency. Pulse duration is an important variable that should receive more attention for an optimal application of NMES in clinical settings.

Effect of Pulsed Shortwave Diathermy on Average Isometric Peak Torque of Quadriceps Muscle in Normal Subjects

Effect of Pulsed Shortwave Diathermy on Average Isometric Peak Torque of Quadriceps Muscle in Normal Subjects

Resistance training improves strength and functional measures in patients with end-stage renal disease

Background: The current study was designed to examine the effect of 12 weeks of resistance training on strength and functional ability in 10 medically stable hemodialysis patients (age, 42.8 ± 4.4 years). Methods: Subjects were tested on four separate occasions, each separated by 6 weeks. The first (T1) and second tests (T2) were controls with no exercise intervention between them. T3 followed 6 weeks of resistance training, and T4 occurred after 12 weeks of training. Variables tested included percentage of body fat, distance covered in the 6-minute walk test, peak torque of quadriceps muscles of the dominant leg, maximal handgrip strength, normal and maximal walking speeds, and time to complete 10 repetitions of the sit-to-stand-to-sit test. Data were analyzed by means of a one-way repeated-measures analysis of variance procedure. Results: Results indicate that after 12 weeks of training, there was a significant (P < 0.05) increase (12.7%) in peak torque at 90°/s (139.1 ± 19.3 nm) compared with T1 and T2 (mean, 124.1 ± 18.7 [SEM]; 123.5 ± 16.9 Nm), respectively. The distance covered during the 6-minute walk was increased (~5%; P < 0.05) compared with baseline (T1, 522.1 ± 46.2 m; 521.9 ± 48.5 m) after 6 weeks of training (548.3 ± 52.1 m) and remained elevated at week 12 (546.5 ± 54.2 m). Maximal walking speed was increased (P < 0.05) by week 12 (195.9 ± 15.4 cm/s) compared with baseline (T1, 182.9 ± 12.7; 185.5 ± 13.0 cm/s). Time to complete 10 repetitions of the sit-to-stand-to-sit test decreased at 12 weeks (17.8 ± 1.9 seconds) versus baseline (T1, 20.3 ± 1.5 seconds; T2, 20.6 ± 5.5 seconds). Conclusion: Resistance training can be used safely to increase strength and functional capacity in stable hemodialysis patients. © 2002 by the National Kidney Foundation, Inc.