A prospective evaluation of strength and endurance of ankle dorsiflexors-plantar flexors after conservative management of lateral malleolar fractures

Objectives: This study aims to evaluate patients with conservatively treated stable lateral malleolar fractures with isokinetic tests. Patients and methods: Between January 2016 and November 2017, a total of 24 patients (12 males, 12 females; mean age 40.8±15.0 years; range, 18 to 68 years) with an isolated stable lateral malleolar fracture treated conservatively with the circular cast were included in this prospective study. Calf circumferences, ankle range of motion (ROM), pain levels, and functional outcomes were recorded. The muscle strengths and endurance of the injured side were compared with the non-injured side. All patients were evaluated by isokinetic test after removal of the cast, and three and six months after the rehabilitation period. Results: The ROM was found to be lower after removal of the plaster cast, compared to the contralateral ankle. During cast removal, we also found that both dorsiflexor and plantar flexor muscle strength decreased by 25.6% and 44.7%, respectively, and decreased to 10.3% and 3.6% at three months post-rehabilitation. At the end of six months, no statistically significant difference was found between the two sides. In the dorsiflexion-plantar flexion endurance values, 37.8% and 54.1% deficit were detected before the rehabilitation protocol, respectively (p<0.05). At three months, these values decreased to 6.1% and 13.6%, respectively and the endurances of the injured sides surpassed the non-injured sides (p<0.05) at six months. Conclusion: Conservative management of stable isolated lateral malleolar fractures with circular cast causes atrophy and decreases strength-endurance of the calf muscles due to immobilization. These changes are expected to diminish over time and functional outcomes are excellent with a good rehabilitation program.

Effects of Traditional Chinese Acupuncture Compared with Sham Acupuncture on the Explosive Force Production by the Forearm Muscles in Female: A Randomized Controlled Trial

Background. Acupuncture can effectively enhance musculoskeletal rehabilitation, with effects such as reduced pain intensity and muscle tension and decreased disability. Objective. The purpose of this study was to determine the efficacy of traditional Chinese acupuncture (TCA) compared with sham acupuncture (SA) in explosive force production by the forearm muscles in females. Methods. A total of 32 subjects were included and randomly assigned to two groups: TCA group (n = 16): stimulated specific acupoints including Quchi (LI11), Shousanli (LI10), Hegu (LI4), Xiaohai (SI8), Tianjing (SJ10), and Waiguan (SJ5) for 15 minutes; SA group (n = 16): using superficial needle insertion at nonacupoints without stimulation. The subjects warmed up for the 3-time isokinetic test with an angular velocity of 30°/s and then performed a set of 15 full flexion (Flex) and extension (Ext) with an angular velocity of 180°/s using the CON-TREX isokinetic test training system recorded as the pretest. After acupuncture for 15 min, perform a set of the same isokinetic movement isokinetic records as the posttest. The average max torque, average work, average power, average peak power, average max speed, and total work were collected to evaluate the forearm explosive force changes. Use two-way repeated measures ANOVA to compare the difference before and after acupuncture between two groups. Results. The results showed that acupuncture conditions (sham acupuncture as well as true acupuncture) and the intervention times (not acupuncture or acupuncture for 15 min) have a significant interaction effect on forearm explosive force and joint stiffness ( P < 0.05 ). The simple main effect showed that the selected parameters of the TCA group increased significantly after acupuncture ( P < 0.05 ), while the SA group did not ( P > 0.05 ). We speculate that the activation of muscle may be related to the selected acupuncture points. Conclusion. Acupuncture can produce excitation in motor nerves and muscles, and nerve stimulation increases the recruitment of motor units, thus improving the muscle explosive force.

CHANGES IN THE FLEXOR AND EXTENSOR MUSCLES AT DIFFERENT SPEEDS

ABSTRACT Introduction: Centrifugal strength is an important element for strength quality. Developing muscle centrifugal strength can effectively increase the stability of lower limbs and reduce the risk of injury. Objective: To explore the characteristics of contractile force of flexor ahods in strength training and rehabilitation training, and the extensor muscles of the knee joint in athletes with different speeds of centripetal force. Methods: The knee joint muscle group of 8 first-level male high jumpers and 8 second-level male high jumpers were tested by isokinetic centrifugal contraction; the angular test velocity was 60 °/s, 120 °/s, 240 °/s, and the indexes included peak torque, relative peak torque (peak torque/body weight), and the peak torque flexural extension ratio. Results: With the centrifugal contraction of the knee joint muscle group (P < 0.05), the second-level high jumpers should increase the ability of the knee flexor muscle group of the take-off leg. In the case of constant velocity centrifugal contraction (P < 0.01), taking off time must be reduced, that is, taking off speed must be accelerated. Conclusions: The difference in the knee joint muscle isokinetic test results is one of the reasons for the difference in knee joint flexor and extensor muscle contractility under the different speed forces of high jumpers. Level of evidence II; Therapeutic studies - investigation of treatment results.

EVALUATION OF BLOOD OXYGEN SATURATION OF HIGH JUMPERS BASED ON ISOKINETIC TEST

ABSTRACT Introduction: An isokinetic test refers to the test of the force of a muscle or muscle group during centripetal and centrifugal movements at a constant speed in the whole range of joint motion by means of a isokinetic force tester. Objective: To explore the application of the knee centripetal flexor and extensor muscle groups in the blood oxygen saturation of high jumpers. Methods: Eighteen teenage female high jumper athletes above level 2 in a city sports school were selected. Their ages was 16.89±1.02 years old; height, 168.31±6.32cm; weight, 55.36±6.75kg. Results: At 60° S and 120° S test speed, the peak moment of the extensor muscle group on the same side of the knee was significantly greater than that of the flexor muscle group (P<0.05), while at 240° S test speed, it was the opposite. There was a significant difference in the peak moment of the flexor muscle group on the left and right side of the knee (P<0.01). Conclusions: The function of the dynamic muscle strength test system is one of the methods of studying the human muscle function. and can be used to test and evaluate the general strength of athletes. Level of evidence II; Therapeutic studies - investigation of treatment results.

L-Glutamine Supplementation Enhances Strength and Power of Knee Muscles and Improves Glycemia Control and Plasma Redox Balance in Exercising Elderly Women

We investigated the effects of oral L-glutamine (Gln) supplementation, associated or not with physical exercises, in control of glycemia, oxidative stress, and strength/power of knee muscles in elderly women. Physically active (n = 21) and sedentary (n= 23) elderly women aged 60 to 80 years were enrolled in the study. Plasma levels of D-fructosamine, insulin, reduced (GSH) and oxidized (GSSG) glutathione, iron, uric acid, and thiobarbituric acid-reactive substances (TBARs) (lipoperoxidation product), as well as knee extensor/flexor muscle torque peak and average power (isokinetic test), were assessed pre- and post-supplementation with Gln or placebo (30 days). Higher plasma D-fructosamine, insulin, and iron levels, and lower strength/power of knee muscles were found pre-supplementation in the NPE group than in the PE group. Post-supplementation, Gln subgroups showed higher levels of GSH, GSSG, and torque peak, besides lower D-fructosamine than pre-supplementation values. Higher muscle average power and plasma uric acid levels were reported in the PE + Gln group, whereas lower insulin levels were found in the NPE + Gln than pre-supplementation values. TBARs levels were diminished post-supplementation in all groups. Gln supplementation, mainly when associated with physical exercises, improves strength and power of knee muscles and glycemia control, besides boosting plasma antioxidant capacity of elderly women.

Preliminary Study of the Effects of Eccentric-Overload Resistance Exercise on Physical Function and Torque Capacity in Chronic Kidney Disease

The purpose of this preliminary study was to describe changes in physical function and torque capacity in adults with chronic kidney disease (CKD) in response to a novel progressive eccentric-overload resistance exercise (ERE) regime. Participants included men (n = 4) diagnosed with CKD according to estimated glomerular filtration rate (eGFR) between 59 and 15 mL/kg/1.73 m2 and not requiring dialysis. Physical function was determined by the Short Physical Performance Battery (SPPB), five repetitions of a sit-to-stand (STS) task, and timed-up and go (TUG). Knee extensor strength was assessed using both isometric and isokinetic contractions and performance fatigability indexes were calculated during a 30-s maximal isometric test and a 30-contraction isokinetic test at 180°/second. None of the patients exhibited significant worsening in their health status after training. Participants demonstrated improvements in several measures of physical function and torque capacity following 24 sessions of ERE. Following training, performance fatigability remained relatively stable despite the increases in torque capacity, indicating the potential for greater fatigue resistance. These findings provide initial evidence for ERE as a potential treatment option to combat declines in physical function and neuromuscular impairments in people with CKD. Future research is required to determine optimal progression strategies for maximizing specific neuromuscular and functional outcomes when using ERE in this patient population.

Concentric and eccentric isokinetic hamstring injury risk among 582 professional elite soccer players: a 10-years retrospective cohort study

Background/AimDifferent authors have tried to correlate the peak isokinetic torque values with the incidence of soccer match injuries. However, due to the wide variety of assessment testing protocols, such an inference becomes difficult. This study aimed to verify the capacity of an isokinetic test to establish injury risk reference values for hamstring strain injuries.MethodsA retrospective cohort study based on isokinetic data and clinical records from the last 10 years was conducted in 582 Brazilian elite-professional soccer players, who were subjected to the same isokinetic test protocol, machine, and tester. A Multivariate Logistic Regression Analysis for Complex Data Sampling was used to generate injury risk statistical indexes.ResultsMultivariate regression analysis of both legs provided important data to identify the cut-off values of Concentric Peak Torque (181.82 Newton/*metres), Concentric Work (236.23 watts) and Concentric Power (130.11 joules).ConclusionsThe injury risk indexes indicate that an increase of just one Newton unit in CPT (Concentric Peak Torque) and CJ (Concentric Power) above those cut-off values, can reduce the risk of future injuries by 2% and 2.7%, respectively.

Diagnostic Validity of an Isokinetic Testing to Identify Partial Anterior Cruciate Ligament Injuries

Objective: To assess the diagnostic validity of an isokinetic testing to detect partial injuries on the anterior cruciate ligament (ACL). Design: Prospective diagnostic study. Settings: Orthopedic clinic, physiotherapy clinic, orthopedic hospital, and diagnostic/image clinic. Participants: Consecutive patients (n = 29) with unilateral knee complaint submitted to physical examination, magnetic resonance images (MRIs), and isokinetic testing prior to surgery of ACL reconstruction. Interventions: Not applicable. Main Outcome Measures: The isokinetic torque curves data from extensor and flexor muscles were converted to frequency domain by fast Fourier transformation and compared with healthy contralateral limb. Differences were categorized as unstable knees and these conclusions were compared with patient’s physical examinations (doctor’s conclusion on ACL integrity) and MRIs (as the radiologist conclusions on ACL integrity). After surgery, all intraoperatively confirmed partial injured patient’s data were collected. The diagnostic accuracy measures to compare the conclusions of all 3 professionals included sensitivity, specificity, positive predictive value, negative predictive value, disease prevalence, positive likelihood ratio, and accuracy—all using a confidence interval of 95%. Results: Compared with MRI, the sensitivity of isokinetic test for an ACL partial injury was 90.00%, specificity 83.33%, positive predictive value 52.94%, negative predictive value 97.56%, and accuracy 84.48%. Compared with physical examination, the sensitivity of isokinetic test for an ACL partial injury was 85.71%, specificity 78.43%, positive predictive value 35.29%, negative predictive value 97.56%, and accuracy 79.31%. Conclusions: This method of isokinetic data analysis through fast Fourier transformation can be used to improve diagnostic accuracy of a difficult detection injury. Even present, a partial ACL injury can produce a stable knee during isokinetic testing and could be used to detect candidates for conservative treatment based on strengthening exercises, reducing surgery risks, and financial and social impact on patient’s life.

Assessment of knee extensor and flexor function using isokinetic test in COPD: impact on exercise capacity

OBJECTIVE: To quantify the relationship between strength and endurance of knee extensor and flexor and exercise capacity in patients with chronic obstructive pulmonary disease (COPD).METHODS: A total of 108 patients with stable COPD (age: 65 years, IQR25–75: 59–72) were enrolled in this cross-sectional study. Knee extensor and flexor function was evaluated using the isokinetic test, and the parameters attained were considered as independent variables. Exercise capacity was evaluated using 6-minute walking test (6MWT) and 30-second sit-to-stand test (30s SST), and the results were considered as dependent variables. The association between lower-limb muscle function and exercise capacity was assessed using multiple regression analysis.RESULTS: The patients mostly had moderate-to-severe airflow obstruction with a post-bronchodilator forced expiratory volume in 1 second (FEV1) of 57.87 ± 17.71% predicted. In multiple regression analysis, flexor total work (TW), extensor endurance ratio (ER), age and FEV1%pred were significantly associated with 6MWT (adjusted R2 = 0.455, P < 0.001). Flexor TW and age were significantly associated with 30s SST (adjusted R2 = 0.355, P < 0.001).CONCLUSION: Knee endurance has a significant relationship with exercise capacity, and knee flexor endurance seems to be an important factor contributing to exercise capacity in COPD patients.