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Biomedical subjects

D H Perrin

Publications and source records attributed to D H Perrin.

48 records · Page 3Linked to original sources
PubMed1995

Effect of ACL Reconstruction and Tibial Rotation on Anterior Knee Laxity.

The anterior cruciate ligament (ACL) is the primary restraint to anterior translation of the tibia on the femur. Research suggests that resistance to anterior translation changes as the tibia is rotated internally and externally. This study assessed the degree to which ACL reconstruction and tibial rotation affects anterior knee laxity. Nine subjects with ACL lesions and functional instabilities participated in the study. Subjects were measured 1 to 10 days before surgery and 6 to 8 months after ACL reconstruction using the KT-1000 knee arthrometer. A mechanical leg stabilizer was used to assess anterior translation at 20 degrees of knee flexion in three positions: internal rotation of 15 degrees , neutral, and external rotation of 15 degrees . Subjects were measured at 89 and 67 N of anterior force. Data were analyzed with a three-factor (test x position x force) repeated measures ANOVA. Following surgery, reduction in laxity (mm) for the three positions (internal rotation, neutral, and external rotation) was 1.9, 2.8, and 3.4, respectively, at 89 N and 1.5, 2.0, and 2.6, respectively, at 67 N. The degree of reduction in laxity (presurgery to postsurgery) was dependent upon rotation and force, and was greatest in external rotation and least in internal rotation pre- to postsurgery. We concluded that ACL reconstruction using a patellar tendon graft significantly decreased anterior tibial translation at all three positions, but a greater amount of reduction was observed postsurgically at the externally rotated position. This supports the theory that mechanical blocks and secondary restraints such as a taut mid-third of the iliotibial tract may interfere with clinical laxity tests in some positions of tibial rotation. Fixing the tibia in an externally rotated position may decrease the effect of secondary restraints and improve sensitivity in testing for ACL laxity.

Journal Article↗
PubMed1994

Medial elbow stability. Clinical implications.

Medial elbow injuries of athletes, such as baseball pitchers and javelin throwers, can prove to be debilitating and may have a negative effect on performance. The most significant injury to the elbow occurs is an ulnar collateral ligament (UCL) sprain or rupture, which compromises the medial stability of the elbow joint. It has been found that the anterior oblique portion of the UCL is the primary stabiliser of the elbow, and that trauma to this complex may significantly hinder normal elbow function. An accurate diagnosis will dictate the degree of injury to the elbow as well as determine the most appropriate means of treatment.

Athletic Injuries↗
PubMed1994

The effects of a functional elbow brace on medial joint stability: a case study.

Medical elbow ligament sprains in athletics can be traumatic and disabling. In this case report, we outline the effect of a prototype functional elbow brace on joint stability in a female collegiate javelin thrower with an ulnar collateral ligament sprain. A valgus force to both elbows was applied using graded stress radiography (Telos GA-II/E stress device) at 0, 5, 10, and 15 kiloPascals (kPa) of pressure. The increase in gap width between the coronoid process and the medial epicondyle was measured from anteroposterior radiographs to determine medial displacement. The brace resulted in less displacement in both injured and noninjured ulnar collateral ligament; injured ulnar collateral ligament demonstrated greater displacement regardless of condition. The brace restored medial stability to the elbow joint by 49%, 38%, and 35% at 5, 10, and 15 kPa of pressure, respectively. The application of the brace may be useful in athletes with ulnar collateral ligament injuries.

Journal Article↗
PubMed1993

Comparison of N-k table offset angles with the human knee flexor torque curve.

The purpose of this study was to dynamically examine various offset angles on the N-K table to determine which offset produces a torque pattern corresponding most closely to the isokinetic torque curve of the knee flexor musculature when tested at 60%. Subjects for the study were five college-age male volunteers (age=21.8+/-1.8 yrs, ht=181.9+/-4.3 cm, wt=88.4+/-12.6 kg). Mean peak isokinetic torque values for the five subjects were measured at 5 degrees increments to represent the human knee flexor torque curve. These were converted to relative mean values by dividing each value by the maximum mean peak torque. Torque curves from four offset angles (90 degrees ,110 degrees ,135 degrees , and 160 degrees ) for the N-K table were obtained by using the Kin Com in the passive mode at 20 degrees /s to push the exercise arm of the N-K table through a range of motion of 0 degrees to 90 degrees while recording torque and angular position. The four torque curves were converted to relative values in a similar manner as for the subjects. Qualitative analysis reveals that the 160 degrees offset angle most closely corresponded to the representative knee flexor isokinetic torque curve, while the 90 degrees offset angle corresponded least. Although these findings would seem to support reconsideration of common clinical practice relative to the use of the N-K table for knee flexor strength development, the 160 degrees offset angle is awkward because it has a tendency to force the user into hyperextension at the beginning phase of motion. As such, practical compromises might include the use of the 110 degrees or 135 degrees offset angle in lieu of the traditionally employed 90 degrees offset angle, or the development of an extension stop that would prevent hyperextension of the knee.

Journal Article↗
PubMed1993

The Reliability Of Three Isokinetic Knee-extension Angle-specific Torques.

To determine the reliability of concentric quadriceps muscle torque at 30 degrees , 60 degrees , and 75 degrees of knee extension, 25 female university students were studied. Each subject was tested on the Kin-Com isokinetic dynamometer on 2 separate days, 7 days apart. The dynamometer's speed was set at 60 degrees ls. Intraclass correlation coefficients for 30 degrees , 60 degrees , and 75 degrees were 0.84 (p<.01), 0.87 (p<.01), and 0.83(p<.01), respectively. The standard errors of the measure were 5.92 N.m, 7.65 N.m, and 7.35 N.m, respectively. Based on the instrumentation and protocol used in this study, we believe angle-specific torques have good reliability. Because of the error size, clinicians using similar methodology to determine angle-specific torques should be cautious when comparing differences between angle-specific torques of less than 12 to 16 N.m.

Journal Article↗
PubMed1993

Effect of preload and range of motion on isokinetic torque in women.

The purposes of this study were to compare the effects of two preload settings (0 N, 75 N) and two ranges of motion (5-90 degrees ROM, 25-70 degrees ROM) on torque output of the knee musculature. Twenty females were randomly assessed for isokinetic concentric (CON) and eccentric (ECC) torque of the knee extensor (EXT) and flexor (FLEX) musculature at a velocity of 1.62 rads.s-1. Two four-way ANOVAs (muscle x mode x range of motion x preload) revealed significant differences in average torque between the preload and range of motion conditions (CONEXT: 5-90 degrees ROM, 75 N = 74.3 +/- 17.2 Nm; 5-90 degrees ROM, 0 N = 68.3 +/- 17.2 Nm; 25-70 degrees ROM, 75 N = 79.0 +/- 13.0 Nm; 25-70 degrees ROM, 0 N = 71.5 +/- 20.8 Nm) (ECCEXT: 5-90 degrees ROM, 75 N = 85.6 +/- 28.6 Nm; 5-90 degrees ROM, 0 N = 82.8 +/- 27.8 Nm; 25-70 degrees ROM, 75 N = 97.7 +/- 23.4 Nm; 25-70 degrees ROM, 0 N = 93.6 +/- 26.5 Nm) (CONFLEX: 5-90 degrees ROM, 75 N = 43.5 +/- 9.2 Nm; 5-90 degrees ROM, 0 N = 43.1 +/- 5.6 Nm; 25-70 degrees ROM, 75 N = 44.2 +/- 8.9 Nm; 25-70 degrees ROM, 0 N = 41.2 +/- 8.9 Nm) (ECCFLEX: 5-90 degrees ROM, 75 N = 56.7 +/- 16.3 Nm; 5-90 degrees ROM, 0 N = 55.6 +/- 17.8 Nm; 25-70 degrees ROM, 75 N = 57.3 +/- 14.0 Nm; 25-70 degrees ROM, 0 N = 51.8 +/- 14.0 Nm) (P < 0.05). No differences in peak torque values were observed. Based on the findings of this study, preload and range of motion should remain constant between and among subjects if average torque is used as a criterion measure.

Adult↗
PubMed1992

Effect of transcutaneous electrical nerve stimulation, cold, and a combination treatment on pain, decreased range of motion, and strength loss associated with delayed onset muscle soreness.

Athletic trainers have a variety of therapeutic agents at their disposal to treat musculoskeletal pain, but little objective evidence exists of the efficacy of the modalities they use. In this study, delayed onset muscle soreness (DOMS) served as a model for musculoskeletal injury in order to: (1) compare the changes in perceived pain, elbow extension range of motion, and strength loss in subjects experiencing DOMS in the elbow flexor muscle group following a single treatment with either transcutaneous electrical nerve stimulation (TENS), cold, a combination of TENS and cold, sham TENS, or 20 minutes of rest; (2) compare the effects of combining static stretching with these treatments; and (3) determine if decreased pain is accompanied by a restoration of strength. DOMS was induced in the non-dominant elbow flexor muscle group in 40 females (age = 22.0 +/- 4.3 yr) with repeated eccentric contractions. Forty-eight hours following exercise, all subjects presented with pain, decreased elbow extension range of motion, and decreased strength consistent with DOMS. Subjects were randomly assigned to 20-minute treatments followed by static stretching. Cold, TENS, and the combined treatment resulted in significant decreases in perceived pain. Treatments with cold resulted in a significant increase in elbow extension range of motion. Static stretching also significantly reduced perceived pain. Only small, nonsignificant changes in muscle strength were observed following treatment or stretching, regardless of the treatment group. These results suggest that the muscle weakness associated with DOMS is not the result of inhibition caused by pain. The results suggest that these modalities are effective in treating the pain and muscle spasm associated with DOMS, and that decreased pain may not be an accurate indicator of the recovery of muscle strength.

Journal Article↗
PubMed1991

Effect of phonophoresis on serum salicylate levels.

The purpose of this investigation was to determine the effect of ultrasound intensity and mode on serum salicylate levels following phonophoresis. Approximately 12-13 g of a salicylate product (Myoflex) was applied to the right anterior forearm of five males and two females. Randomly ordered ultrasound treatment intensities (0.0 W.cm-2; 1.5 W.cm-2, pulsed 50%; and 1.5 W.cm-2, continuous) were applied through the salicylate-containing product for a 5 min duration. A 7.0 ml blood sample was drawn from the left anterior forearm prior to each treatment and again 2 h after treatment. Analysis of variance indicated that none of the topical salicylate treatments produced an increase in serum salicylate levels. These findings suggest that there is no appreciable absorption of salicylate into the bloodstream following topical application of salicylate with or without the use of ultrasound. Since any penetration of salicylate through the skin would result in an increase in serum salicylate levels, the efficacy of phonophoresis to introduce medication into the subdermal tissue is questionable. These findings suggest that a critical review of phonophoresis in general is indicated.

Administration, Cutaneous↗
PubMed1989

Cold exposure injuries: prevention and treatment.

A variety of cold exposure injuries were discussed, including frostnip, chilblains, trench foot, frostbite, and hypothermia. The usual precipitating factors for each were discussed along with the clinical course, the pathophysiology, and management from the perspective of one being in the field or backcountry. Prevention is the key to all cold-related problems as adequate treatment is often not possible out of the hospital setting. Detailed recommendations were made for all conditions, relative to treatment and prevention, with special emphasis on hypothermia.

Athletic Injuries↗
PubMedDate not supplied

Instrumented arthrometry for diagnosing partial versus complete anterior cruciate ligament tears.

Nineteen patients with the clinical diagnosis of anterior cruciate ligament injury were examined by KT-1000 arthrometry before arthroscopy in an effort to differentiate partial from complete tears. To this end, the KT-1000 arthrometer was equipped with a strain gauge and processor that permitted the required force to increase the anterior displacement by 1-mm increments, to be read on a light-emitting diode. The measured force has been plotted against anterior displacement expressed in non-linear increments along the x-axis to allow for the viscoelastic nature of the ligament. The results show that stress-strain diagrams of partially torn and completely torn ligaments are similar to those obtained by graded stress radiography. Using arthroscopy as the standard of measurement, partial tears can be differentiated from complete tears with a sensitivity of 80% and a specificity of 100%. The figures for complete tears versus partial tears are 100% and 80%, respectively. Graded arthrometry with x-y recording of the force-displacement relationship that allows for the viscoelastic qualities of ligament further extends the capabilities of instrumented arthrometry.

Adolescent↗
PubMedDate not supplied

The biophysical effects of ultrasound on median nerve distal latencies.

PURPOSE: Previous studies have documented the lack of ultrasound's non-thermal effects on nerve conduction using frequencies of 1 MHz and 870 kHz. The analyses and conclusions were reached, despite only one study incorporating pulsed ultrasound. The purpose of this study was to determine the biophysical effects of continuous wave (CW) and pulsed wave (PW) ultrasound on median nerve motor and sensory latencies using common frequencies of 1.0 and 3.0 MHz. SUBJECTS: Fifteen healthy subjects (8 males, 7 females, age = 23.5 + 4.44 yrs, height = 171.2 + 10.7 cm, weight = 67.5 + 7.9 kg) without a history of neurological or musculoskeletal injury to their non-dominant arm volunteered for testing. METHODS AND MATERIALS: Subjects were exposed in counterbalanced order to five ultrasound treatment conditions: (1) 1 MHz, 1.0 W/cm2, 8 min., (2) 1 MHz, 1.0 W/cm2, 50% PW, 8 min., (3) 3.0 MHz, 1.0 W/cm2, CW, 8 min., (4) 3.0 MHz, 1.0 W/cm2, 50% PW, 8 min., (5) placebo, 0.0 W/cm2, 8 min. Dependent measures for motor and sensory latencies, and subcutaneous temperatures were taken pretreatment, at 2, 4 and 6 minutes during treatment, and immediately post-treatment. Separate two within repeated measures ANOVA were used for each dependent measure. RESULTS: Analysis revealed significant interactions for motor latencies [F (16,224) = 52.77, p < .001], sensory latencies [F (16,224) = 41.10, p < .001], and subcutaneous temperatures [F (16,224) = 52.77, p < .001]. Tukey's HSD post hoc analyses confirmed that nerve latencies responded similarly to subcutaneous temperature changes during and after ultrasound treatment. CONCLUSIONS: Alterations in nerve latencies from ultrasound on healthy nerves appeared to be related to temperature changes induced by ultrasound's thermal effects, and not by non-thermal or mechanical effects.

Adult↗