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The Cambridge Ramped Treadmill Test (CRTT) is an incremental, multistage exercise test (I: steady-state walk, II: walk ramped speed, III: walk ramped incline, and IV: run ramped speed on flat). It is typically deployed as a submaximal test with flexible test termination criteria, making it an attractive option for population-based studies of cardiorespiratory fitness. We conducted a study in healthy adults to test the validity of maximal oxygen consumption estimates (VO2 max; ml O2·kg-1·min-1) predicted from CRTT heart rate response using several methods: a heart rate-to-work rate linear regression method across several test termination criteria, either when a percentage of age-predicted maximal heart rate was achieved (50% through 100%) or at the end of distinct CRTT stages (II, III, and IV); and two single-point walk-test calibration methods using data from either CRTT stage I (low-point method) or stage II (high-point method). For estimates from the linear regression method, prediction bias ranged from −3.0 to −1.6 ml O2·kg-1·min-1 and Pearson’s r ranged from 0.57 to 0.79 for endpoints at percentages of age-predicted maximal heart rate; results were similar for stages III and IV endpoints, but predictions using data only up to stage II had poorer agreement. Agreement was moderate when using the low-point (mean bias: −4.3 ml O2·kg-1·min-1; Pearson’s r: 0.71) and high-point (mean bias: −3.5 ml O2·kg-1·min-1; Pearson’s r: 0.69) methods. Heart rate response to the CRTT can be used to predict VO2max with acceptable validity in common epidemiological scenarios.

Aging is associated with impaired upper limb proprioceptive acuity, as reflected by decreased position matching accuracy with increasing task complexity and movement extent. Most studies have primarily used single-joint or planar paradigms to examine age-related changes in proprioception. It is unclear whether these changes can be generalized to more complex multi-joint movements, where additional sensory feedback may affect performance. Since age-related declines in cognitive function may impair the ability to integrate multiple sources of sensory feedback, deficits in position matching ability in older adults may persist when tasks are performed in three-dimensional space. The accuracy with which young and older participants reproduced remembered reference hand positions was assessed under different experimental conditions. Participants matched target locations located directly to the front or 45° to the side relative to the midline using the preferred and non-preferred arms. Either the same (i.e., ipsilateral matching) or the opposite (i.e., contralateral matching) arm was used to reproduce the target location. No differences in matching accuracy were found between young and older participants when matching ipsilaterally. When matching contralaterally, accuracy was worse in older participants for target locations located to the side, which may reflect age-related changes in the perception of peripersonal space. In contrast to previous studies, accuracy did not differ between the preferred and non-preferred arms in either group. These results extend previous findings demonstrating age-related impairments in proprioceptively guided arm movements when interhemispheric transfer is required.

Knee osteoarthritis (OA) is a chronic disease characterized by articular cartilage damage, pain, and weakness. Ambulating stairs is a leading source of pain in people with OA, and disease progression may be marked by asymmetrical gait abnormalities. The purpose of this study was to assess relative peak knee extension torque and Step-Up-and-Over (SUO) test performance asymmetries in individuals with knee OA. Forty-six male Veterans with knee OA (age = 61.6 yrs. ± 5.6) enrolled in the study. Functional performance was assessed via the SUO test, which involves ascending/descending an 8-inch box on a force plate. SUO test outcomes included force-time parameters representing step-up force, step-down force, and force-time curve smoothness. Peak torque was measured using isokinetic dynamometry (180 deg/s). Self-reported symptoms and physical function were evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS). Force-time curve smoothness was the only SUO test outcome significantly different in the less involved leg (mean = -8.27 ±.55) compared to the more involved leg (mean = -8.48 ±.57, p

The applied use of eccentric muscle actions for physical rehabilitation may utilize the framework of periodization. This approach may facilitate the safe introduction of eccentric exercise and appropriate management of the workload progression. The purpose of this data-driven Hypothesis and Theory paper is to present a periodization model for isokinetic eccentric strengthening of older adults in an outpatient rehabilitation setting. Exemplar and group data are used to describe the initial eccentric exercise prescription, structured familiarization procedures, workload progression algorithm, and feasibility of the exercise regimen. Twenty-four men (61.8 ± 6.3 years of age) completed a 12-week isokinetic eccentric strengthening regimen involving the knee extensors. Feasibility and safety of the regimen was evaluated using serial visual analog scale (VAS, 0–10) values for self-reported pain, and examining changes in the magnitude of mean eccentric power as a function of movement velocity. Motor learning associated with the familiarization sessions was characterized through torque-time curve analysis. Total work was analyzed to identify relative training plateaus or diminished exercise capacity during the progressive phase of the macrocycle. Variability in the mean repetition interval decreased from 68 to 12% during the familiarization phase of the macrocycle. The mean VAS values were 2.9 ± 2.7 at the start of the regimen and 2.6 ± 2.9 following 12 weeks of eccentric strength training. During the progressive phase of the macrocycle, exercise workload increased from 70% of the estimated eccentric peak torque to 141% and total work increased by 185% during this training phase. The slope of the total work performed across the progressive phase of the macrocycle ranged from −5.5 to 29.6, with the lowest slope values occurring during microcycles 8 and 11. Also, mean power generation increased by 25% when eccentric isokinetic velocity increased from 60 to 90° s−1 while maintaining the same workload target. The periodization model used in this study for eccentric exercise familiarization and workload progression was feasible and safe to implement within an outpatient rehabilitation setting. Cyclic implementation of higher eccentric movement velocities, and the addition of active recovery periods, are featured in the proposed theoretical periodization model for isokinetic eccentric strengthening.