Biomedical subjects

M C Morrissey

Publications and source records attributed to M C Morrissey.

7 recordsLinked to original sources

PubMed1991

Static pre-load effect on knee extensor isokinetic concentric and eccentric performance.

The effect of two static pre-load levels on isokinetic concentric (CON) and eccentric (ECC) performance of the knee extensors at 90 degrees.s-1 was evaluated in 35 healthy subjects. The low pre-load level was 50 N, and the high level was 75% of a maximal voluntary isometric contraction, performed at the start angles of 100 degrees (CON) and 30 degrees (ECC) of knee flexion. A two-way ANOVA with two repeated measures (load and angle) and a Newman-Keuls post hoc analysis were performed to compare the interaction of pre-load and angle at every 5 degrees in the ROM. The differences in average torque, peak torque, and peak torque angle between the pre-load levels were also analyzed with repeated-measures t-tests. The high pre-load condition had a significant increase in torque at 99, 95, 90, and 85 degrees concentrically and 31, 35, 40, 45, and 50 degrees eccentrically. In comparing the two pre-load conditions over the whole torque curve, there was a significant difference in average torque values of both CON and ECC, no significant difference in peak torque in either contraction, and a significant shift in peak torque angle with CON contractions only.

Adult↗

PubMed1989

Reflex inhibition of thigh muscles in knee injury. Causes and treatment.

There are several common findings and contradictions noted in the research related to thigh muscle reflex inhibition and sequelae that occur with knee joint injury. Reflex inhibition may be measured directly by electromyography, or the sequelae of reflex inhibition may be measured, as commonly occurs in the clinic setting. Electromyography is useful in determining the causes of reflex inhibition. The most frequently cited causes of thigh muscle reflex inhibition in knee injury are pain, joint effusion and knee immobilisation. The other measurement methods described vary from thigh circumference measurement to muscle biopsy. These methods are useful in determining the magnitude and duration of the deleterious sequelae that affect the thigh muscles after reflex inhibition. Finally, there is selectivity of reflex inhibition after knee joint injury: the quadriceps versus the hamstrings, the different components of the quadriceps muscle group, and the different types of muscle fibres. In light of these findings, several suggestions have been offered for prevention of reflex inhibition and for techniques that can be applied to rehabilitate the most affected muscle group: the quadriceps femoris. Techniques used to prevent or limit the amount of reflex inhibition include cryotherapy, transcutaneous electrical nerve stimulation, iontophoresis, phonophoresis, joint mobilisation, rest and proper positioning of the knee in rest and exercise. Electromyostimulation, electromyographic biofeedback and traditional exercise training are 3 methods used to rehabilitate the quadriceps.

Humans↗

PubMed1988

Electromyostimulation from a clinical perspective. A review.

A proliferation of the research analysis and clinical use of electromyostimulation has occurred in sports medicine in the last decade. This manuscript will review the important findings from a clinical perspective. Specifically, this article will address the advantages of electromyostimulation over voluntary exercise indicating its greater effectiveness in the early period of rehabilitation when reflex inhibition is dominant. Other advantages of electromyostimulation include its: usefulness in training one component of an agonist muscle group; effectiveness during joint immobilisation; and possible role in altering specific muscle fibre types and enzymes. In order to facilitate the use of electromyostimulation a number of factors require consideration including proper selection of stimulus parameters, joint position and electrode size, type and placement. In addition, the research findings relative to the use of electromyostimulation at different stages of recovery as well as the concern of whether electromyostimulation should be used with or without voluntary activation of the muscle are addressed. There have been few clinical studies of the use of electromyostimulation after peripheral joint injury. The studies that have been performed focus primarily on quadriceps femoris rehabilitation after knee injury and these were classified according to diagnostic groups and discussed in this article. Finally, directions for future research are described with the hope that the great scientific effort displayed to date will be continued.

Athletic Injuries↗

PubMed1988

A review of the literature related to trunk muscle performance.

In the past, there has been no comprehensive review of the literature pertaining to different methods of assessing trunk muscle strength. This review describes the different studies that have been performed, and determines the hierarchy of strength values and agonist/antagonist strength ratios for the trunk musculature. In general, the strength hierarchy consists of, from strongest to weakest: extension, flexion, side bending, and rotation. The agonist/antagonist ratio for extension/flexion is 1.30 and for rotation and side bending, motion to the right approximately equals motion to the left. Changes in the relative strengths of the different trunk muscle groups is affected by spinal pathology, and this is discussed. Possible clinical implications and direction for future research are delineated based on the findings of this review.

Back↗

PubMed1987

Development of a clinical physical therapy research program.

Clinical physical therapy research is important for the continued growth of the physical therapy profession. Such research results in improved patient care and heightens the professional standing of the physical therapy field. One of the major barriers to clinical physical therapy research is unfamiliarity with the research process by practicing physical therapists. The purpose of this article is to present a model for developing a clinical physical therapy research program that may assist novice investigators interested in initiating clinical physical therapy research at their facility.

Models, Theoretical↗

PubMedDate not supplied

The effects of electrical stimulation on the quadriceps during postoperative knee immobilization.

Immobilization of the knee after anterior cruciate ligament (ACL) reconstruction results in marked thigh atrophy and decrease in quadriceps strength that may prolong the rehabilitation program of the injured athlete. Fifteen male volunteers undergoing ACL reconstruction were divided into two groups, stimulation (during immobilization) and nonstimulation. Measurements of thigh circumference and isometric quadriceps strength were tested preoperatively, immediately after cessation of cast immobilization (6 weeks), and at 9 and 12 weeks postoperatively. The changes in circumference and strength between the first preoperative test and all subsequent tests were compared for statistical significance (Student's t-test, P less than 0.5) between the two groups. The decrease in quadriceps strength of the stimulation group during immobilization was significantly less than that of the nonstimulation group, although later differences between the two groups were not significant. There were no significant differences in thigh atrophy between the two groups. In conclusion, isometric quadriceps torque decreases resulting from immobilization can be significantly lessened by application of electrical stimulation during immobilization. Electrical stimulation to the quadriceps does not significantly alter thigh circumference changes that occur during immobilization.

Adolescent↗

PubMedDate not supplied

Assessment of quadriceps/hamstring strength, knee ligament stability, functional and sports activity levels five years after anterior cruciate ligament reconstruction.

The purpose of this study was to examine individuals 5 years after ACL reconstruction and analyze changes involving strength, stability, function, and sports activities. Nineteen males and six females, mean age = 31.4 +/- 7.31 years, participated in this study. Fifteen subjects had received extraarticular and ten subjects had received intraarticular ACL reconstructions. Subjects completed a 100 point subjective functional activity questionnaire and a sports participation survey. Knee ligament stability was assessed during an objective knee examination. Isokinetic quadriceps and hamstring muscle strength were tested at 240 and 120 deg/sec using the Cybex II dynamometer. Anterolateral rotatory instability and positive Lachman were elicited on the operated leg for 80% of the subjects. No significant relationship was found between objective instability and the functional activity score. For the intraarticular group, a significant correlation (P less than 0.05) was found between increased quadriceps and hamstring strength on the operated leg and return to functional activities. Subjects' functional activity score was positively correlated (P less than 0.001) with their ability to participate in sports. Subjects participating in sports involving cutting and twisting motions were less successful in returning to their preinjury participation levels and reported more subjective complaints of pain, swelling, and/or instability. These results indicate that long-term progressive rehabilitation emphasizing increased quadriceps and hamstring strength to approximate the nonoperated leg may enhance successful return to functional and sports activities after ACL reconstruction.

Adult↗