Oxidative stress and inflammatory responses following an acute bout of isokinetic exercise in obese women with knee osteoarthritis.

BACKGROUND: Obesity is associated with osteoarthritis and it is accompanied by chronic inflammation and elevated oxidative stress. Strengthening-type exercise is used in knee osteoarthritis (KOA) rehabilitation. This study determined how acute isokinetic exercise influences inflammatory responses of obese middle-aged women with KOA. METHODS: Ten obese women with KOA and 10 age/weight-matched controls performed an isokinetic exercise protocol. Assessment of performance (knee extensor/flexor torque), muscle soreness (DOMS), knee flexibility (KJRM), and pain, and blood collection were performed pre-exercise, post-exercise, and at 24h post-exercise. Blood was analyzed for creatine kinase activity (CK), lactate dehydrogenase activity (LDH), CRP, leukocytes, uric acid, IL-6, TBARS, lipid hydroperoxides (LPX), protein carbonyls (PC), oxidized (GSH) and reduced glutathione (GSSG), total antioxidant capacity (TAC), catalase activity, and glutathione peroxidase activity (GPX). RESULTS: Physical function remained unaltered by exercise (only torque at 90°/s decreased at 24h). Exercise increased DOMS throughout recovery but KJRM and pain remained unchanged. CK, LDH, and uric acid increased similarly in both groups. CRP remained unaffected by exercise while IL-6 increased only post-exercise. TBARS, PC, LPH, GSSG, and TAC increased only post-exercise in both groups. GSH and GSH/GSSG declined post-exercise and normalized thereafter. Catalase and GPX increased only in patients post-exercise. CONCLUSION: Isokinetic exercise induces only a mild inflammatory response of very short duration (<24h) without affecting physical function and pain in KOA patients suggesting that moderate strengthening-type exercise may be safe for this patient cohort. These results indicate that KOA patients may be able to receive another exercise stimulus after only 48h. CLINICAL RELEVANCE: Isokinetic exercise produces minimal inflammation and pain in knee osteoarthritis patients, could be performed every 48h during rehabilitation, and up-regulates patients' antioxidant system.

Muscle performance following an acute bout of plyometric training combined with low or high intensity weight exercise.

To determine the time course of performance responses after an acute bout of plyometric exercise combined with high and low intensity weight training, a 3-group (including a control group), repeated-measures design was employed. Changes in performance were monitored through jumping ability by measuring countermovement and squat jumping, and strength performance assessment through isometric and isokinetic testing of knee extensors (at two different velocities). Participants in both experimental groups performed a plyometric protocol consisting of 50 jumps over 50 cm hurdles and 50 drop jumps from a 50 cm plyometric box. Additionally, each group performed two basic weight exercises consisting of leg presses and leg extensions at 90-95% of maximum muscle strength for the high intensity group and 60% of maximum muscle strength for the low intensity group. The results of the study suggest that an acute bout of intense plyometric exercise combined with weight exercise induces time-dependent changes in performance, which are also dependent on the nature of exercise protocol and testing procedures. In conclusion, acute plyometric exercise with weight exercise may induce a substantial decline in jumping performance for as long as 72 hours but not in other forms of muscle strength.

Time course of changes in performance and inflammatory responses after acute plyometric exercise.

The objectives of the present investigation were to study the inflammatory and performance responses after an acute bout of intense plyometric exercise during a prolonged recovery period. Participants were randomly assigned to either an experimental group (P, n = 12) that performed intense plyometric exercises or a control group (C, n = 12) that rested. The delayed onset of muscle soreness (DOMS), knee range of motion (KROM), creatine kinase (CK) and lactate dehydrogenase (LDH) activities, white blood cell count, C reactive protein (CRP), uric acid (UA), cortisol, testosterone, IL-6, IL-1b strength (isometric and isokinetic), and countermovement (CMJ) and static (SJ) jumping performance were measured at rest, immediately postexercise and at 24, 48, 72, 96, and 120 hours of recovery. Lactate was measured at rest and postexercise. Strength remained unchanged throughout recovery, but CMJ and SJ declined (p < 0.05) by 8-20%. P induced a marked rise in DOMS, CK, and LDH (peaked 24-48 hours postexercise) and a KROM decline. An acute-phase inflammatory response consisting of leukocytosis (postexercise and at 24 hours), an IL-6, IL-1b, CRP, and cortisol elevation (during the first 24 hours of recovery) and a delayed increase of UA (peaked at 48 hours) and testosterone (peaked at 72 hours) was observed in P. The results of this investigation indicate that performing an acute bout of intense plyometric exercise may induce a short-term muscle damage and marked but transient inflammatory responses. Jumping performance seems to deteriorate for as long as 72 hours postexercise, whereas strength appears to remain unchanged. The acute-phase inflammatory response after a plyometric exercise protocol appears to follow the same pattern as in other exercise models. These results clearly indicate the need of sufficient recovery between successive plyometric exercise training sessions.

Young tennis players and balance performance.

The purpose of the present study was to investigate the effect of a tennis training session on the balance performance of young tennis players. The study was conducted on 36 elite tennis players (age 14 +/- 2 years; body mass 55 +/- 6 kg; body height 165 +/- 6 cm; mean +/- SD) participating in the national young tennis championship. Balance performance was assessed before and immediately after a tennis training session (pre-training and post-training, respectively). The balance assessment was performed with 2 different balance boards and the Biodex Stability System. In addition, dynamometric measurements of peak isokinetic moment in the knee flexors and extensors were performed pre and post tennis training session, to quantify the degree of muscle fatigue induced by the tennis training session. One-way analysis of variance with repeated measures was used to test for differences in balance performance and in isokinetic performance between pre and post tennis training session. The data analysis revealed no significant differences (p > 0.05) in balance performance, whereas there were significant differences in knee joint moment production between pre and post tennis training measures. Although the tennis training session of the present study had no significant effect (p > 0.05) on any of the balance performance indicators examined, there was a decline in balance performance, which suggests that different level of fatigue for an extended period (games) will have greater effect on balance performance. It is suggested that a tennis-specific balance exercise program should be included in the tennis training session.

Assessment of patients with neck pain: a review of definitions, selection criteria, and measurement tools.

OBJECTIVE: The purpose of this literature review was to synthesize the existing literature on various definitions, classifications, selection criteria, and outcome measures used in different studies in patients with neck pain. METHODS: A literature search of MEDLINE and CINAHL through September 2008 was performed to gather articles on the reliability, validity, and utility of a wide variety of outcome measurements for neck pain. RESULTS: Different types of definitions appear in the literature based on anatomical location, etiology, severity, and duration of symptoms. Classifications according to severity and duration of pain and the establishment of selection criteria seem to play a crucial role in study designs and in clinical settings to ensure homogeneous groups and effective interventions. A series of objective tests and subjective self-report measures are useful in assessing physical abilities, pain, functional ability, psychosocial well-being, general health status, and quality of life in patients with neck pain. Self-administered questionnaires are commonly used in clinical practice and research projects. CONCLUSIONS: Because of multidimensionality of chronic neck pain, more than just one index may be needed to gain a complete health profile of the patient with neck pain. The instruments chosen should be reliable, valid, and able to evaluate the effects of treatment.

Isolated vs. complex exercise in strengthening the rotator cuff muscle group.

The purpose of this study was to compare 2 different training modes in improving shoulder cuff muscular performance. Thirty-nine participants were randomly assigned into 3 groups: the isolated group exercised using 2-kg dumbbells; the complex group used a protocol with complex exercises; and the control group had no training. All participants trained for 6 weeks (3 times per week) and were evaluated isokinetically before (pretest) and after the training period (posttest). Results showed that the complex group significantly improved their muscular performance, but the isolated group did not, indicating that isolated exercises are only effective when the training goal is to strengthen the weaker muscle group, but they must be replaced by more complex and closed-kinetic exercises in order to obtain considerable improvement of the rotator cuff strength. The authors propose that a strengthening program should start with isolated movements for better stimulation of the weaker muscles and continue with complex exercise for more impressive strengthening.