ABSTRACT
OBJECTIVE: The purpose of this study was to compare the kinematics, muscle activation, and force production between Parkinson's patients and healthy, age-matched participants during sit-to-stand transfers. DESIGN: This cross-sectional study employed a 2x2x3 multivariate analysis of variance to test for significant differences between and within groups. BACKGROUND: The underlying mechanisms that predispose an individual to lose strength during the clinical progression of Parkinson's disease have proved to be elusive, especially during performance of functional tasks such as the sit to stand transfer. METHODS: Twenty-four men (mean age: 71.5 years) categorized as Parkinson's patients (n = 13) and healthy adults (n = 11) participated in this study. Two force platforms measured antero-posterior and vertical force components as well as peak torque. Muscle activation was measured by a six channel, bilateral electromyography system. A lower-body kinematic assessment was conducted utilizing a high-speed motion analysis system. RESULTS: No statistically significant differences were found between groups for the outcome variables measured. However, Parkinson's patients did exhibit significant within-group bilateral differences for the variables of knee angle at seat-off, peak vertical force and peak torque. CONCLUSION: Data from this study reveal that persons with mild to moderate Parkinson's disease exhibit moderately altered bilateral mechanics when performing a sit to stand transfer compared to their healthy peers. RELEVANCE: The inability to produce constant equilateral force when performing functional tasks could be an indicator for the increased propensity of falls or other instabilities in this population.
Subject(s)
Electromyography/methods , Hip Joint/physiopathology , Knee Joint/physiopathology , Models, Biological , Movement , Muscle Contraction , Parkinson Disease/physiopathology , Posture , Aged , Biomechanical Phenomena/methods , Computer Simulation , Cross-Sectional Studies , Humans , Male , Middle Aged , Muscle, Skeletal/physiopathology , Stress, Mechanical , Torque , Weight-BearingABSTRACT
BACKGROUND: The performance of daily tasks, such as stair climbing or lifting an object, requires both muscle strength and power. Age-associated reductions in strength and power can affect an older adult's ability to complete daily tasks such as stair climbing and lifting a child. METHODS: The purposes of this study were to determine whether power training was more efficacious than strength training for improving whole-body physical function in older adults and to examine the relationship between changes in anaerobic power and muscle strength and changes in physical function. Thirty-nine men and women (mean age +/- SD = 72.5 +/- 6.3 years) with below-average leg extensor power were randomly assigned to control (C, n = 15), strength-training (ST, n = 13) or power-training (PT, n = 11) groups. The ST and PT groups met 3 days per week for 16 weeks; the C group maintained usual activity and attended three lectures during the course of the study. Primary outcome measures included the Continuous Scale Physical Functional Performance test, maximal strength, and anaerobic power. RESULTS: After baseline was controlled for, the Continuous Scale Physical Functional Performance test total score was significantly greater for the PT group than for the ST (p =.033) and C (p =.016) groups. Maximal strength was significantly greater for the ST group than for the C group (p =.015) after the intervention. There was no significant difference between groups for peak anaerobic power. CONCLUSIONS: Power training was more effective than strength training for improving physical function in community-dwelling older adults.
Subject(s)
Exercise/physiology , Muscle, Skeletal/physiology , Physical Education and Training/methods , Physical Endurance/physiology , Weight Lifting/physiology , Activities of Daily Living , Aged , Aged, 80 and over , Anaerobic Threshold , Confidence Intervals , Female , Geriatric Assessment , Humans , Male , Physical Exertion , Probability , Reference Values , Residence Characteristics , Sensitivity and SpecificityABSTRACT
BACKGROUND: Challenging daily tasks, such as transferring heavy items or rising from the floor, may be dependent on the ability to generate short bursts of energy anaerobically. The purposes of this study were to determine if strength-trained (ST) older adults have higher anaerobic power output compared with non-strength-trained (NST) older adults and to determine the relationship between anaerobic power and performance-based physical function. METHODS: Thirty-five men and women (age 71.5 +/- 6.4 years, mean +/- SD; NST: n = 18, ST: n = 17) were grouped by training status. Outcome variables included relative anaerobic power (Wingate test), physical function measured with the Continuous Scale Physical Functional Performance Test (CS-PFP, scaled 0 to 100), and anthropometric lean thigh volume (LTV). Analysis of covariance (with age and sex as covariates) was used to determine group differences in the dependent variables listed above. Pearson's r was used to determine the relationship between anaerobic power, CS-PFP total score (TOT), and CS-PFP lower body strength domain score (LBS). RESULTS: The ST group had significantly higher mean anaerobic power (NST 58.9 +/- 16 W/l, ST 96.3 +/- 23 W/l), CS-PFP total (NST 61.2 +/- 13, ST 73.7 +/- 8), and LBS (NST 54.1 +/- 17, ST 70.9 +/- 8) compared with the NST group (p <.05). However, LTV was similar for both groups (NST 3.323 +/- 0.75; ST 3.179 +/- 0.79), which suggests that the ST group had higher muscle quality compared with the NST group. Anaerobic power was significantly related to TOT (r =.611, p =.001) and LBS (r =.650, p =.001). CONCLUSIONS: High levels of physical function in ST older adults may in part be explained by higher levels of anaerobic power associated with strength training.
