The influence of oblique-angle forced exercise in surgically destabilized stifle joints is synergistic with bone, but antagonistic with cartilage in an ovine model of osteoarthritis

Large animal models of osteoarthritis are a necessary testing ground for FDA approval of human medicine applications. Sheep models have advantages over other available large animals, but development and progression of osteoarthritis in sheep is exceedingly slow, which handicaps progress in development of potential treatments. We combined oblique angle forced exercise to increase stress on the stifle, with surgical destabilization to hasten the development of osteoarthritis in ewes. Methods for early detection of clinical signs included radiography, urine, and serum biomarker assays and gait analysis and ex vivo we used microcomputed tomography and macroscopic joint analysis. Our model was able to produce clinically detectable signs of osteoarthritis in a relatively short period (14 weeks). Changes in bone were highly correlated between microcomputed tomography and radiographic analysis and changes in cartilage correlated well between urinary glycosaminoglycan levels and serum aggrecanase analyses. Exercise improved the negative effects of destabilization in bone but exacerbated the negative effects of destabilization in cartilage. These observations suggest that we may need to consider treatments for bone and cartilage separately. These results represent an improved large animal model of osteoarthritis with rapid onset of disease and superior detection of bone and soft tissue changes

The effects of whole body vibration on jump performance in dancers

Effets d'un programme d'utilisation d'un appareil de vibration du corps entier (Galileo 2000) pendant 10 jours sur la performance de saut vertical, en contre-bas et avec contre-mouvement chez des danseuse

Effect of pelvic, hip, and knee position on ankle joint range of motion

OBJECTIVE: To determine if pelvic posture, hip, and knee positions influence range of motion about the ankle joint. STUDY DESIGN: Quasi-experimental repeated measures. SETTING: Biomechanics laboratory in a university setting. PARTICIPANTS: Eleven men and six women free of ankle joint trauma. MAIN OUTCOME MEASURES: Range of motion about the ankle joint. RESULTS: ANOVA revealed a significant difference for position main effect on ankle joint range of motion (p=0.01). Post-hoc tests revealed that ankle joint range of motion significantly decreased as participants moved from flexion (i.e., 90 degrees hip and 90 degrees knee), to supine, and to long sitting (47.3 degrees , 38.8 degrees , and 16.4 degrees ; p\u3c0.05). No significant differences were revealed for pelvic posture (p=0.64). CONCLUSIONS: These findings indicate that pelvic posture may not influence ankle joint range of motion regardless of hip and knee joint positions. However, the combination of hip flexion and knee extension (i.e., long sitting) produces the greatest deficits in ankle joint range of motion

Effects of Flywheel Resistance Training on Muscle Function and Sport-Specific Performance in Collegiate Club Water Polo Players

Purpose: This study investigated the effects of flywheel squat training on lower body muscle function adaptions and sport-specific performance in collegiate club water polo players. Methods: Thirteen collegiate club water polo athletes (5 women, 8 men) performed flywheel squat training for 4 weeks. Isokinetic knee extension (KE) peak power (PP) and peak torque (PT), flywheel squat peak power (FPP) and mean power (FMP), countermovement jump (CMJ), in-water jump height (WJH) and foot speed were assessed at baseline (Pre1), 4 weeks (Pre2), and 8 weeks (Post) with the first 4 week block being a control period and the second 4 week block being the experimental training. Throughout the training period muscle soreness was assessed using a VAS scale, and FPP and FMP were assessed during every other session. Results: Isokinetic KE PP and PT increased from Pre1 to Post, and FPP and FMP increased between Pre1 and Post, and Pre2 and Post. CMJ and foot speed were unchanged. WJH displayed a change between Pre1 and Post. FPP increased 19% from session 2 to 4 and FMP increased 27% from session 2 to 6, and each remained elevated through session 8. Conclusion: 4 weeks of flywheel squat training in collegiate club water polo players elicited large gains (47-52%) in flywheel-specific squat power, but did not influence sport-specific performance measures including CMJ, WJH, and foot speed. Water-based exercises and stretch-shortening cycle movements (plyometrics) in combination with effective resistance training programs, which may include flywheel-based training, are likely needed for marked sport skill improvements

Trunk muscle activity during spine stabilization exercises performed in a pool

OBJECTIVES: To compare trunk muscle activity levels among a variety of therapeutic aquatic exercises designed for patients with low back pain. STUDY DESIGN: Quantitative observational laboratory study. SETTING: Sports medicine clinic housed in a University. PARTICIPANTS: Eleven physically active males aged 25.7 ± 5.53 years. MAIN OUTCOME MEASURES: Surface electromyographic (EMG) data from muscles rectus abdominis (RA), external oblique (EO), lower abdominals (LA), multifidus (MT), and erector spinae (ES) were recorded and then normalized to a maximal voluntary contraction. RESULTS: EMG values during abdominal bracing and Swiss ball exercises for muscles RA, EO, LA, and ES were significantly greater than most other exercises tested that included pelvic tilt, marching, hip abduction, and alternating arm exercises (P = .04-.001). EMG values of muscle LA were also greater for the abdominal hollowing exercise, whereas muscle MT displayed the greatest EMG values during the hip abduction exercise when compared to most other exercises tested (P = .02-.001). CONCLUSIONS: The aquatic exercises that maximize trunk muscle activity in the healthy males studied are abdominal bracing and Swiss ball exercises. Some muscles were selectively activated during abdominal hollowing (LA) and hip abduction (MT) exercises when compared to most other exercises

Acute aquatic treadmill exercise improves gait and pain in people with knee Osteoarthritis

Abstract Objective: To examine the acute effects of aquatic and land treadmill exercise on gait kinematics as well as the level of disease-specific and movement-related pain for individuals with osteoarthritis. Design: Quasi-experimental crossover design. Setting: Biomechanics laboratory. Participants: Participants (NZ14; age, 43e64y) diagnosed with osteoarthritis at the knee (nZ12), osteoarthritis at the knee and ankle (nZ1), or osteoarthritis at the knee and hip (nZ1). Interventions: Participants performed 3 exercise sessions separated by at least 24 hours in 1 week for each mode of exercise (aquatic treadmill and land treadmill). Main Outcome Measures: Gait kinematics and pain were measured before and after each intervention. Results: The angular velocity gain score during stance for left knee extension was improved by 38% after aquatic treadmill exercise (PZ.004). Similarly, during swing, the gain scores for angular velocity were also greater for left knee internal rotation and extension by 65% an

Strength and conditioning for throwing in cricket

In cricket, the ability to throw a ball at high velocity with great accuracy is critical to successful performance and often determines the outcome of matches. The skill of cricket fielding incorporates a movement phase and a pick-up and throw phase aimed at decreasing run rate or producing a run out of the opposition. A major issue in cricket is the risk of injury to players attributed to an acute spike in throwing intensity and volume during practice and matches. This article discusses strength and conditioning practices that may reduce the prevalence of throwing-related injuries and improve throwing performance