John Greany

Translation of Submaximal Exercise Test Responses to Exercise Prescription Using the Talk Test.

Foster, C, Porcari, JP, Gibson, M, Wright, G, Greany, J, Talati, N, and Recalde, P. Translation of submaximal exercise test responses to exercise prescription using the talk test. J Strength Cond Res 23(9): 2425-2429, 2009-The exercise intensity at the Talk Test (TT) has been shown to be highly correlated with objective physiological markers, a useful outcome marker in patients with heart disease, a useful tool for avoiding exertional ischemia, and responsive to both positive and negative changes in exercise capacity. This randomized observational study evaluated the ability of the intensity at the TT during exercise testing to define absolute training workloads. Sedentary adults (n = 14) performed an incremental Balke type exercise test (3.0-3.5 mph at 0% grade, +2% grade every 2 minutes). Heart rate (HR), rating of perceived exertion (RPE), and TT were evaluated at each stage. Subsequently, the subjects performed 3 × 20-minute exercise bouts with the workload over the last 10 minutes of each bout equal to the absolute intensity at the stage preceding the LP (LP-1), at the last positive stage of the TT (LP), and at the first equivocal stage of the TT (EQ). During LP-1, LP, and EQ, HR was 140 ± 23, 151 ± 20, and 160 ± 21 bpm, or 73 ± 11, 79 ± 9, and 82 ± 9 % HRmax; RPE (CR scale) was 3.6 ± 1.5, 4.4 ± 1.8, and 6.3 ± 2.2. The TT Score-ranked as 1 = comfortable speech, 2 = slightly uncomfortable speech, and 3 = speech not comfortable-was 1.4 ± 0.5, 1.8 ± 0.4, and 2.6 ± 0.5 LP-1, LP, and at EQ, LP, respectively. The results suggest that to prescribe absolute training intensity from the TT and to get appropriate HR, RPE, and TT responses in sedentary individuals during training, the workload needs to be based on the intensity approximately 1 stage (∼1.0-1.2 metabolic equivalents) below the LP stage observed during an incremental test.

Effects of acute static stretching of the throwing shoulder on pitching performance of national collegiate athletic association division III baseball players.

Haag, SJ, Wright, GA, Gillette, CM, and Greany, JF. Effects of acute static stretching of the throwing shoulder on pitching performance of National Collegiate Athletic Association Division III baseball players. J Strength Cond Res 24(2): 452-457, 2010-Stretching is a common component of an athletic warm-up even though many studies have demonstrated that pre-event static stretching can decrease strength and power performance. The purpose of this study was to examine the effects of acute static stretching of the throwing shoulder on pitching velocity and accuracy of National Collegiate Athletic Association Division III baseball players. Twelve collegiate baseball players, including 6 pitchers and 6 position players, participated in the study. Each participant completed 2 separate testing protocols over a span of 4-6 days. In the experimental condition (SS), 6 static stretches were applied to the throwing shoulder after an active warm-up. After a rest period of 5-10 minutes, participants were allowed 5 warm-up pitches from a pitching mound. Participants then threw 10 pitches measured for velocity and accuracy. The control condition (NS) followed the same procedure but did not include the 6 static stretches. Testing was conducted in an indoor practice facility during normal team practice. No significant differences were found in average velocity, maximum velocity, or accuracy measures when comparing the SS and NS conditions. These results suggest that acute static stretching of the throwing shoulder does not have a significant impact on baseball pitching performance. Static stretching of the shoulder may be performed during a warm-up before a throwing activity.

Suppression of the Vertical Vestibulo-ocular Reflex in Older Persons at Risk of Falling

A case-control design was used to assess eye-head-trunk coordination for community-dwelling elders performing a stand-walk task. Eighteen elders with a high risk of falling were matched to 18 subjects with low risk on the basis of age, living status (living alone or with someone) and category of residence (independent living or assisted living facility). Standard electro-oculography was used in conjunction with an electromagnetic tracking device to measure eye and head-trunk motion, respectively. For the low-risk group, the mean slope of gaze-head and gaze-trunk relationships was significantly greater than zero (0.91 and 0.64, respectively), whereas high-risk elders did not demonstrate slope magnitudes significantly different from zero (0.52 and 0.16, respectively) due to large inter-subject variations. While the majority of subjects showed some counter-rotation of the eyes with head pitch, a greater percentage of subjects in the high-risk group did not suppress this response and consequently gaze and gaze velocity overcompensated for head pitch. These findings suggest that the vertical vestibulo-ocular reflex is not adequately suppressed during the stand-walk task in elders who are at a high risk of falling. Possible mechanisms contributing to these findings are discussed.A case-control design was used to assess eye-head-trunk coordination for community-dwelling elders performing a stand-walk task. Eighteen elders with a high risk of falling were matched to 18 subjects with low risk on the basis of age, living status (living alone or with someone) and category of residence (independent living or assisted living facility). Standard electro-oculography was used in conjunction with an electromagnetic tracking device to measure eye and head-trunk motion, respectively. For the low-risk group, the mean slope of gaze-head and gaze-trunk relationships was significantly greater than zero (0.91 and 0.64, respectively), whereas high-risk elders did not demonstrate slope magnitudes significantly different from zero (0.52 and 0.16, respectively) due to large inter-subject variations. While the majority of subjects showed some counter-rotation of the eyes with head pitch, a greater percentage of subjects in the high-risk group did not suppress this response and consequently gaze and gaze velocity overcompensated for head pitch. These findings suggest that the vertical vestibulo-ocular reflex is not adequately suppressed during the stand-walk task in elders who are at a high risk of falling. Possible mechanisms contributing to these findings are discussed.

Saccade to stepping delays in elders at high risk for falling

Background and aims: Visually guided stepping is an essential function in many normal activities of daily living requiring the coordination of eye movements with precise foot placement. The objective of this investigation was to compare the saccade-footlift latency in community dwelling elderly identified as high-risk for falling with elderly who are at a low-risk of falling during a walking task that requires precise foot placement. Methods: A non-randomized between-group repeated measures design was employed using independently living elderly volunteers from the Minneapolis, MN community. Thirty older adults volunteered to participate in the study; fifteen who had a history of a fall in the previous 12 months or a prolonged score on a fall risk screening instrument (Timed Up and Go test), and fifteen elders who had not fallen and had a negative score on the screening instrument. Subjects were required to walk along a pathway of 4 irregularly spaced stepping targets. The time between horizontal saccadic eye movement to the initiation of footlift (saccade-footlift latency) was the primary dependent measure. Results: The mean saccade-footlift latency between high-risk (H-R) elderly and low-risk (L-R) elderly was statistically different (mean H-R 940 ms, L-R 825 ms; F1,3=7.45, p=0.006). The H-R elderly also performed more slowly on the cognitive test — Trail Making Test Part B (mean H-R 195 s, L-R 129 s; F1,2=7.21, p=0.01). The results suggest that there is an association between horizontal saccades, stepping and cognition for elderly at risk for falling. Conclusions: The timing of saccades and precise foot placement in older persons living in the community are associated with fall risk status and cognitive status. The prolonged time for saccade-footlift in H-R elderly may be attributed to greater central nervous system processing time necessary to plan precise foot placements or volitional processing delays in postural control due to fall risk status. In addition, age related changes in cognitive functions appear to be associated with saccade stepping interaction when performing a visually guided stepping pattern and may influence the ability to coordinate precise lower extremity movements.

Peak Muscle Activation, Joint Kinematics, and Kinetics During Elliptical and Stepping Movement Pattern on a Precor Adaptive Motion Trainer

Kinematic, kinetic, and electromyography data were collected from the biceps femoris, rectus femoris (RF), gluteus maximus, and erector spinae (ES) during a step and elliptical exercise at a standardized workload with no hand use. Findings depicted 95% greater ankle plantar flexion (p = .01), 29% more knee extension (p = .003), 101% higher peak knee flexor moments (p < .001), 54% greater hip extensor moments (p < .001), 268% greater anterior joint reaction force (p = .009), 37% more RF activation (p < .001), and 200% more ES activation (p < .001) for the elliptical motion. Sixteen percent more hip flexion (p < .001), 42% higher knee extensor moments (p < .001), and 54% greater hip flexor moments (p = .041) occurred during the step motion. Biomechanical differences between motions should be considered when planning an exercise regimen.

Models to Predict Fall History and Fall Risk for Community-Dwelling Elderly

ABSTRACT The objective of this study was to compare fall-risk models for the prediction of 1-year fall history in community-dwelling elderly persons. The study design was a descriptive analysis of factors associated with retrospective fall history for individuals living in community-based independent living facilities. Thirty-three older adults (10 men and 23 women, mean age ± standard deviation, 82.6 ± 5.5 years) volunteered to participate. The main outcome measure was multivariate logistic regression models using a minimal set of predictor variables for predicting 1-year fall history and fall-risk status. The results showed that a fall history prediction model using age, gait velocity, and time to complete Trails Making Test Part B yielded 76% of overall predictive accuracy (75% sensitivity, 76% specificity). A second logistic regression with gait speed eliminated was used to identify fall-risk status (fall history plus a positive score on the Timed Up and Go test) with similar results. These findings suggest that these variables are critical for identifying elderly fallers and those at risk for falls.

Plantar Loading Asymmetry in American Indians with Diabetes and Peripheral Neuropathy, with Diabetes Only, and Without Diabetes

BACKGROUND We investigated plantar loading asymmetry during gait in American Indians with and without diabetes and with diabetes and peripheral neuropathy. METHODS A convenience sample of 96 American Indians with and without diabetes was divided into three groups: 20 with diabetes and peripheral neuropathy, 16 with diabetes without peripheral neuropathy, and 60 with no history of diabetes (control group). Plantar loading was measured during barefoot walking across a pressure platform. Five trials were collected per foot during level walking at a self-selected speed using the two-step method. Asymmetry in peak pressure-time integral and peak plantar pressure were calculated from ten plantar regions and compared among groups. RESULTS Significant pressure-time integral asymmetry occurred across the forefoot regions in American Indians with diabetes and peripheral neuropathy compared with the other two groups. Significant peak plantar pressure asymmetry occurred in the third metatarsal region in both groups with diabetes (with and without peripheral neuropathy) compared with the control group. CONCLUSIONS Overall, American Indians with diabetes seemed to show greater asymmetry in plantar loading variables across the forefoot region compared with those in the control group. Specifically, individuals with diabetes and peripheral neuropathy had the greatest amount of forefoot pressure-time integral asymmetry. Significant peak plantar pressure asymmetry occurred in the third metatarsal region of the forefoot in those with diabetes with and without peripheral neuropathy. Loading asymmetry may play a role in the development of foot ulcers in the forefoot region of American Indians with peripheral neuropathy and diabetes.