Self-paced resistance training and walking exercise in community-dwelling older adults: effects on neuromotor performance.

BACKGROUND: Resistance-training intervention studies have demonstrated meaningful health benefits in older adults; however, most have used exercises performed at specific intensities on expensive equipment, which limit their widespread applicability. We tested whether two self-paced, less expensive exercise protocols could be effective and safe for modifying neuromotor performance and functional capacity in community-dwelling adults 65-95 years of age. METHODS: One hundred and thirty-one subjects were randomized to a novel resistance training, walking, or control group. Subjects determined their level of resistance or walking intensity (self-paced) on a session-by-session basis. Muscle strength, balance, reaction time, stair climbing speed, and a timed pen pickup task were measured before and after the intervention period. Exercisers met three times per week for 10 months. RESULTS: Significant improvements in tandem stance and single-legged stance with eyes open times and stair climbing speed were seen in both exercise groups. In addition, resistance trainers improved their muscle strength and ability to pick up an object from the floor and reduced the number of missteps taken during tandem walking, and walkers reduced tandem walking time. Controls showed no significant improvement in any variable. CONCLUSIONS: The two self-paced exercise protocols were effective at improving neuromotor performance and functional capacity in the study sample and show promise as a safe, effective, cost-efficient, acceptable exercise model for primary and secondary prevention in the general population of community-dwelling older adults.

Geometric variables from DXA of the radius predict forearm fracture load in vitro.

The purpose of this investigation was to determine the cross-sectional geometry of the radius in female and male cadaveric specimens using dual-energy X-ray absorptiometry (DXA), to measure the accuracy of this technique compared with a digitizing procedure, and to measure the correlation between these DXA-based geometric variables and the load required to produce a forearm fracture. Paired intact forearms were scanned at a distal site and at a site approximately 30% of the forearm length from the distal end. The cross-sectional area and the moments of inertia of two sections at 10 and 30% of the forearm length were computed from the X-ray attenuation data. One member of each pair was then sectioned at the 30% location, which is mostly cortical bone, and the section was traced on a digitizing pad. The other forearm was loaded to failure in a servohydraulic materials test system. The DXA-based area and moment of inertia at 30% correlated significantly with the digitized results (r2 = 0.93 for area; r2 = 0.95 for moment; P < 0.001). The conventional bone mineral density from DXA did not associate significantly with failure load, but the minimum moment of inertia and the cross-sectional area at 10% correlated in a strong and significant manner with the forearm fracture force (r2 = 0.67 for area; r2 = 0.66 for moment; P < 0.001). The determination of radial bone cross-sectional geometry, therefore, should have better discriminatory capabilities than bone mineral density in studies of bone fragility and fracture risk.

Musculoskeletal assessment and training: the young athlete.

The primary purpose of a preparticipation physical examination is to identify risk factors that may predispose an athlete to physical and/or psychological injury. Inclusion of a physiological assessment complements the more traditional preparticipation health examination by contributing valuable information toward the specific physical strengths and weaknesses of the young athlete. This information when combined with the orthopedic and medical components of a preparticipation examination can dramatically enhance the safety of sports participation.