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Biomedical subjects

K W Hayes

Publications and source records attributed to K W Hayes.

6 recordsLinked to original sources
PubMed1992

Differential muscle strength decline in osteoarthritis of the knee. A developing hypothesis.

The ratio of quadriceps to hamstrings muscle strength (Q/H ratio) is important for the stability of the knee and for protection from excessive stress. The purpose of this study was to explore whether the Q/H ratio is altered in patients with osteoarthritis (OA). Subjects were 43 patients with physician-diagnosed OA of the knee (mean age, 65.61 years; SD, 12.74). Isometric knee flexor and extensor strength was measured with a hand-held dynamometer. Both muscle groups were weak, with relatively greater weakness in the quadriceps muscles. The mean Q/H ratio of 1.43 (SD, 0.39) was below ratios reported for young healthy adults (2.0). The low Q/H ratio might be caused by the inability to correct the measurement for gravity, but a liberal estimate of gravity correction raised the ratio only to 1.71 (SD, 0.47). The low Q/H ratio was probably not caused by physiologic changes due to aging, because the correlation between the ratio and age was low (-0.04). Since the correlation of the Q/H ratio with the usual level of pain (measured by a visual analogue scale) was negative (-0.26), the low ratio might be explained by reflex inhibition due to pain associated with disease.

Adult↗
PubMed1992

Effect of ultrasound on mobility in osteoarthritis of the knee. A randomized clinical trial.

Ultrasound increases soft tissue extensibility and may be an effective adjunct in the treatment of knee contractures secondary to connective tissue shortening. A randomized clinical trial was conducted to determine the effectiveness of ultrasound in relieving stiffness and pain in patients (age mean = 67.5 years, SD = 13.0) who had osteoarthritis (OA) and a chronic knee contracture. Subjects received 12 treatments of exercise preceded by either ultrasound (n = 34) or sham ultrasound (n = 35) and a blinded evaluation at baseline, after treatment, and 2 months after treatment. MANCOVA controlling for baseline scores showed that there were no significant differences in knee active range of motion (ROM) (goniometry) or pain (visual analogue scale) between experimental and control groups. Possible explanations for the no difference finding involve dosage issues, muscle shortening, transiency of effects, and the effects of exercise. Paired t-tests revealed that both groups significantly improved (p less than 0.05) in active ROM, pain, and gait velocity, and maintained improvement for at least 2 months. Although ultrasound may not contribute to the management of patients with chronic knee stiffness and OA, benefits of the exercise program and increased activity secondary to program participation probably influenced the overall improvement.

Aged↗
PubMed1992

The effect of awareness of measurement error on physical therapists' confidence in their decisions.

This study examined whether physical therapists understand the meaning of measurement error and whether information about measurement error affects their decisions. One of four versions of two physical therapy problems was mailed to 500 randomly selected physical therapists. Therapists were asked to define reliability and error of measurement, to estimate the error of measurement of two assessments, and to make decisions about an intervention based on specific measurements. They were also asked to rate their confidence in those decisions. Problems varied on the presence or absence of measurement information and on the difference between an observed measurement and a criterion measurement against which the observed measurement must be compared to make a decision. The response rate was 62%; respondents represented a typical profile of practicing physical therapists. The therapists understood reliability, but they did not correctly describe the relationship between reliability and error of measurement. Their estimates of the error of measurement of the two assessments were reasonable for only one procedure. The presence or absence of measurement information and difference between observed and criterion measurements affected their confidence, albeit inappropriately, in only one problem. Confidence was not affected by the therapists' level of experience, type of reading, formal study, or degree earned. Therapists responded to the two problems differently. The problems involved different measures, roles, utilities, and structures. The process of decision making does not generalize to all decision types. Measurement principles and strategies of use in decision making must be emphasized in physical therapy curricula so that physical therapists can consider the quality of their assessment data in making clinical decisions.

Anthropometry↗
PubMed1990

Therapeutic ultrasound in the treatment of musculoskeletal conditions.

This paper presents a quantitative synthesis of the literature addressing the effectiveness of ultrasound in selected musculoskeletal conditions. Pain and range of motion appear to improve following ultrasound treatment in acute periarticular inflammatory conditions and osteoarthritis, but not in chronic periarticular inflammatory conditions. Placebo response and experimenter expectancy bias can not be ruled out as explanations for the positive results. The literature concerning the therapeutic efficacy of ultrasound for pain and immobility in musculoskeletal conditions is therefore inconclusive. Well-designed clinical trials are needed to resolve this question.

Bone Diseases↗
PubMed1989

Reliability of a new device used to measure shoulder subluxation.

The purposes of the study were to determine the reliability of a new device used to quantify shoulder subluxation and to estimate its standard error of measurement. The device is an L-shaped thermoplastic jig with a metric tape measure embedded in it. A sliding beak-like marker, which can be anchored with a thumbscrew, is used to identify landmarks and to measure the amount of subluxation. Eight male and two female hemiplegic subjects, 40 to 80 years old, consented to be measured for subluxation. Three standardized subluxation measurements were taken by one investigator to determine the reliability with a single rater. One measurement was taken by a second investigator and compared with the first measurement obtained by the first investigator to determine the reliability using more than one rater. Both investigators were experienced physical therapists. Each measurement was read by the other investigator, who disassembled the jig and cleaned the marks from the patient between measurements. For both analyses, an analysis of variance for repeated measurements reflected no differences between measurements attributable to raters. The unbiased intraclass correlation coefficient for a single measurement by a single rater was .89 (p less than .01) and for more than one rater was .74 (p less than .01). The standard error of measurement was +/- 0.77 mm for a single rater and +/- 1.20 mm for more than one rater. We recommend the jig as a tool to measure shoulder subluxation in patients.

Adult↗