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R J Robertson

Publications and source records attributed to R J Robertson.

99 records · Page 6Linked to original sources
PubMed1976

Influence of pretest waiting time and duration of induction on kinesthetic aftereffect.

The influence of pretest hand-resting time and induction time on kinesthetic aftereffect was determined for 22 males and females. Aftereffect was assessed with the apparatus of Koehler and Dinnerstein (1947). Three separate tests of aftereffect were administered. Each was preceded by either a 10-, 20-, or 30-min. hand-resting period. Significant differences in aftereffect were not found between pretest conditions. Scores were also determined for varying induction times at each pretest condition. Induction periods totaling 90-, 180-, and 300-sec. were used. Aftereffect was significantly less pronounced following 90 than 180 sec. of induction for the 10-and 20-min. pretest conditions but was the same following 90, 180, and 300 sec. of induction for the 30-min. condition. Results indicated that less than 300 sec. of induction could be used regardless of the duration of the pretest period. However, because the internal validity of the 180-sec. score was significantly better than the 90-sec. score, it was concluded that at least 180 sec. of induction were needed.

Female↗
PubMedDate not supplied

Neuromuscular activation and RPE in the quadriceps at low and high isometric intensities.

INTRODUCTION: The purpose of this study was to examine neuromuscular activation and ratings of perceived exertion (RPE) at 10% and 80% quadriceps MVC in healthy males. METHODS: Seventeen college-aged volunteers (mean age = 22.6 years, mean height = 178.9 cm, mean weight = 78.8 kg) were assessed for isometric EMG activity of the vastus medialis (VM) and vastus lateralis (VL) at 10% and 80% MVC, and RPE at 80% MVC. Perceived exertion was measured with a modified category ratio scale (CR-10) and was anchored with 1 high and 1 low anchor. Raw EMG signals were sampled via telemetry (rate = 1,000 Hz) and integrated (3 sec) for each contraction for each muscle (bandpass = 16-500 Hz, CMRR = 130 dB). A one-sample t-test was performed for each variable and 95% confidence intervals were calculated. RESULTS: Means and CI for each variable are as follows: 10% MVC VM IEMG (t16 = 5.05, p < 0.001, .95 CI = 3.11 +/- 1.3), 80% MVC VM IEMG (t16 = 22.51, p < 0.001, .95 CI = 73.2 +/- 6.89), 10% MVC VL IEMG (t16 = 8.10, p < 0.001, .95 CI = 9.41 +/- 2.47), 80% MVC VL IEMG (t16 = 39.56, p < 0.001, .95 CI = 87.32 +/- 4.68), and 80% MVC RPE (t16 = 11.85, p < 0.001, .95 CI = 5.24 +/- 0.93). DISCUSSION: The major findings illustrate an apparent underestimation of RPE at 80% MVC for the quadriceps. Neuromuscular activation appears to be lower than the expected force output at both intensities for the VM while VL activation corresponded closely at 10% MVC and was higher at 80% MVC.

Adult↗
PubMedDate not supplied

Imaging the pleura.

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Diagnosis, Differential↗
PubMedDate not supplied

Fatigue in women with myocardial infarction.

This study measured fatigue in women 6 weeks after myocardial infarction. Fatigue was experienced by the women as chronic, generalized, intermittent, and longstanding. More than one third of the women attributed their fatigue directly to the heart attack or hospitalization. Significant relations were found between fatigue and the physiological dimension of the Sickness Impact Sale (SIP), the Perceived Health Assessment and Risk Protection Survey (PHARPS), and the site of infarction, as well as with the psychological dimension of the SIP. There was an inverse significant relation between fatigue scores and the Psychological General Well-Being (PGWB) Index. Although not reaching statistical significance, fatigue scores for women 65 and older were higher than for younger women.

Adult↗