Search Results (7)

Background and Objectives: The increased prevalence of knee osteoarthritis (OA) and need for total knee arthroplasty (TKA) indicate a growing need for effective prehabilitation. The effect of preoperative home exercise programs (HEPs) on gait in patients with severe knee OA is under-investigated. This study aimed to evaluate the influence of an 8-week preoperative HEP on gait characteristics, leg extensor muscle strength, knee function, and health status in women with severe knee OA scheduled for TKA and to compare them with healthy control data. Material and Methods: Eighteen women with severe knee OA (KOA, aged 61.8 ± 1.6 years) and ten age-matched healthy women (CON) participated in this study. The KOA group performed an HEP with 15 exercises aimed at improving lower limb muscle strength, motion, balance, and coordination. Gait spatiotemporal and kinetic characteristics during the loading response, isometric leg extensor strength, knee active range of motion (AROM), and The Western Ontario and McMaster Universities Arthritis Index (WOMAC) were investigated. Associations between characteristics were analyzed. Results: Improvements in ground reaction force (GRF) during the loading response of gait, leg extensor muscle strength, the knee AROM, and the WOMAC index were found post-HEP. The KOA group demonstrated lower (p < 0.05) spatiotemporal and GRF characteristics than the CON group. Knee extension moment (KEM) was lower pre-HEP (p < 0.05) but did not differ significantly from the CON group post-HEP. Gait characteristics and WOMAC were associated with leg extensor muscle strength and knee AROM and pain in the KOA group. Conclusions: An eight-week preoperative HEP improved GRF and KEM during the loading response of gait, muscle strength, knee function, and self-reported knee OA-related health status in women with severe knee OA. Preoperative HEP before TKA, focusing on leg extensor muscle strength, range of motion, and pain relief, is an effective alternative to supervised exercise therapy in women with severe knee OA. Full article

The aim of this study was to compare seat pressure asymmetries before and after 30 min cycling at constant intensity in association with pelvic anthropometric parameters and skeletal muscle fatigue. Twelve male road cyclists aged 18–30 years (mean training experience 9.9 ± 2.5 years) participated. Pelvic anthropometric data and body composition were measured with dual-energy X-ray absorptiometry. Participants performed 30 min cycling at 50% peak power output at constant intensity on a cyclus-2 ergometer. Muscle fatigue during cycling was assessed by surface electromyogram spectral mean power frequency (MPF) for the back, gluteal, and thigh muscles. The pressure mapping system was used to assess sitting symmetry before and after the cycling exercise. At the end of cycling, MPF was decreased (p < 0.05) in the dominant side’s erector spinae muscle and the contralateral gluteal muscle. After the exercise, a significant (p < 0.05) asymmetry in seat pressure was observed under the ischial tuberosity based on the peak pressure right to left ratio, whereas peak pressure decreased under the left ischial tuberosity. After the exercise, the relationship (p < 0.05) between pelvis width and pressure under the ischial tuberosity occurred on the dominant side of the body. In conclusion, an asymmetry was revealed after the constant-load cycling exercise by peak pressure ratio right to left side. Further studies should address the role of seat pressure asymmetries before and after cycling exercises at different intensities and durations. Full article

Background and Objectives: Musculoskeletal injuries are a major health hazard among military personnel. Previous research has proposed several exercise-based strategies for prevention. The purpose of this study was to investigate the effect of an exercise-based injury-prevention program on the incidence of musculoskeletal injury, motor performance and psychosocial status. Materials and Methods: Thirty-six Estonian Military Academy cadets were randomly assigned into either an intervention or control group. The intervention group followed a neuromuscular exercise-based injury-prevention warm-up program, three times per week for 6 months. The control group continued with the usual warm-up. The main outcome measure was injury incidence during the study period. Additionally, evaluation of isokinetic lower-extremity strength, postural sway, physical fitness and psychosocial status was included pre- and post-intervention. Results: During the 6-month study period, the musculoskeletal injury incidence was 43% in the intervention group and 54% in the control group (RR = 0.8; 95% CI = 0.41 to 1.99). The noted 20% risk reduction was not statistically significant (p = 0.59). Furthermore, there were no statistically significant differences between the intervention and control group in motor performance or psychosocial status measures. Conclusions: In conclusion, no effect of the exercise-based injury-prevention program on injury risk, motor performance or psychosocial status could be detected. Full article

The kynurenine pathway (KP) is gaining attention in several clinical fields. Recent studies show that physical exercise offers a therapeutic way to improve ratios of neurotoxic to neuroprotective KP metabolites. Antioxidant supplementation can blunt beneficial responses to physical exercise. We here studied the effects of endurance training in the form of sprint interval training (SIT; three sessions of 4–6 × 30 s cycling sprints per week for three weeks) in elderly (~65 years) men exposed to either placebo (n = 9) or the antioxidants vitamin C (1 g/day) and E (235 mg/day) (n = 11). Blood samples and muscle biopsies were taken under resting conditions in association with the first (untrained state) and last (trained state) SIT sessions. In the placebo group, the blood plasma level of the neurotoxic quinolinic acid was lower (~30%) and the neuroprotective kynurenic acid to quinolinic acid ratio was higher (~50%) in the trained than in the untrained state. Moreover, muscle biopsies showed a training-induced increase in kynurenine aminotransferase (KAT) III in the placebo group. All these training effects were absent in the vitamin-treated group. In conclusion, KP metabolism was shifted towards neuroprotection after three weeks of SIT in elderly men and this shift was blocked by antioxidant treatment. Full article

Sprint interval training (SIT) has emerged as a time-efficient training regimen for young individuals. Here, we studied whether SIT is effective also in elderly individuals and whether the training response was affected by treatment with the antioxidants vitamin C and E. Recreationally active elderly (mean age 65) men received either vitamin C (1 g/day) and vitamin E (235 mg/day) or placebo. Training consisted of nine SIT sessions (three sessions/week for three weeks of 4-6 repetitions of 30-s all-out cycling sprints) interposed by 4 min rest. Vastus lateralis muscle biopsies were taken before, 1 h after, and 24 h after the first and last SIT sessions. At the end of the three weeks of training, SIT-induced changes in relative mRNA expression of reactive oxygen/nitrogen species (ROS)- and mitochondria-related proteins, inflammatory mediators, and the sarcoplasmic reticulum Ca²⁺ channel, the ryanodine receptor 1 (RyR1), were blunted in the vitamin treated group. Western blots frequently showed a major (>50%) decrease in the full-length expression of RyR1 24 h after SIT sessions; in the trained state, vitamin treatment seemed to provide protection against this severe RyR1 modification. Power at exhaustion during an incremental cycling test was increased by ~5% at the end of the training period, whereas maximal oxygen uptake remained unchanged; vitamin treatment did not affect these measures. In conclusion, treatment with the antioxidants vitamin C and E blunts SIT-induced cellular signaling in skeletal muscle of elderly individuals, while the present training regimen was too short or too intense for the changes in signaling to be translated into a clear-cut change in physical performance. Full article

The aim of this study was to assess associations between performance in the timed up-and-go (TUG) and six-minute walk distance (6MWD) with physiological characteristics in young and old healthy adults. Thereto, we determined TUG, 6MWD, normalised jump power, centre of pressure displacement during 1-leg standing, forced expiratory volume in 1 s, percentage of age-predicted maximal heart rate (HR%) and height in 419 healthy young (men: 23.5 ± 2.8 years, women: 23.2 ± 2.9 years) and old (men: 74.6 ± 3.2 years, women: 74.1 ± 3.2 years) adults. Normalised jump power explained 8% and 19% of TUG in young (p = 0.025) and older men (p < 0.001), respectively. When fat mass percentage and age were added to normalised jump power, 30% of TUG was explained in older men (R²_adj = 0.30, p < 0.001 to 0.106). Appendicular lean muscle mass percentage (ALM%) and age were the best determinants of TUG for older women (R²_adj = 0.16, p < 0.001 to 0.01). HR% explained 17–39% of 6MWD across all groups (R²_adj = 0.17 to 39, p < 0.001). In conclusion, in men, jump power was a key determinant for TUG, while in old women only it was the ALM%. As HR% was the most important determinant of 6MWD, motivational bias needs to be considered in the interpretation of this test. Full article

Background and Objective. Frozen shoulder syndrome (FSS) causes pain and restriction of movement in the shoulder. The aim was to assess changes in shoulder muscle isometric maximal voluntary contraction (MVC) force and active range of motion (AROM) in patients with frozen shoulder syndrome (FSS) after manipulation under general anesthesia (MUA).
Material and Methods. In total, 18 patients with FSS (9 women and 9 men) with a mean age of 53.6 years (SD, 9.7) participated in this study. MVC force of shoulder flexors, adductors, and internal and external rotators was measured by a handheld dynamometer. AROM in the same directions was measured goniometrically. The patients were screened according to the intensity of pain by day and at night. The data were collected before MUA and 1 and 6 months after MUA. A significant reduction in MVC force and AROM was noted before MUA in the involved extremity as compared with the uninvolved extremity (P<0.05). These parameters for the involved extremity were significantly increased 1 month after MUA (P<0.05). However, 6 months after MUA, MVC force and AROM did not differ significantly compared with the uninvolved extremity (P>0.05), whereas AROM of flexion and external rotation remained significantly reduced (P<0.05). A significant reduction in shoulder pain by day and at night was recorded 1 and 6 months after MUA (P<0.05).
Conclusions. In the patients with FSS, the fastest improvement of MVC force and AROM occurred following the first month after MUA. However, 6 months after MUA, shoulder muscle MVC force for the involved extremity did not differ significantly as compared with the uninvolved extremity, whereas the shoulder AROM in flexion and external rotation remained lower. Full article