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Biomedical subjects

J Perry

Publications and source records attributed to J Perry.

At least 109 records · Page 6Linked to original sources
PubMed1987

Energy cost of three-point crutch ambulation in fracture patients.

The energy consumption associated with unilateral nonweight-bearing (three-point) crutch ambulation was evaluated in a group of 25 newly injured fracture patients immobilized in a long or short leg cast. After 5 min of crutch ambulation, the rate of oxygen uptake was 32% greater than the value for normal walking (averaging 15.7 ml/kg-min); the heart rate was 53% greater than normal (averaging 153 beats/min); and the respiratory quotient was markedly elevated (averaging 1.03). In those subjects able to ambulate for 10 min, these values averaged 17.6 ml/kg-min and 173 beats/min, approaching the peak values for maximal upper extremity exercise. The prescription of three-point crutch ambulation is a severe exercise challenge requiring strenuous arm and shoulder exertion under anaerobic conditions. These findings account for the common clinical experience that the newly injured fracture patient, unable to weight bear on an injured limb and requiring crutches, is a severely restricted ambulator.

Adult↗
PubMed1987

Distal rectus femoris transfer.

A major concern in the management of children with cerebral palsy is crouch gait with its excessively flexed knee and hip stance. Earlier, attention was given to the flexed hip and it was assumed that the rectus femoris, as an active component of the quadriceps, contributed an unwanted effect. Proximal surgical release of the rectus from its attachment on the ilium was recommended. However, dynamic electromyographic records of 45 children with cerebral palsy demonstrated that the rectus more commonly was active in the swing phase, and such an approach is appropriate only when electromyography confirms that rectus function is occurring in stance. The recording technique must be capable of differentiating rectus femoris action from that of the underlying vasti, which surface electrodes are not able to do. Past experience indicates that routine inclusion of a proximal rectus femoris release (without confirmation that the muscle's action was limited to stance) resulted in the patient having a stiff-legged gait. Hence the actions of the rectus femoris need closer attention.

Cerebral Palsy↗
PubMed1987

Rectus femoris transfer to improve knee function of children with cerebral palsy.

Stance phase stability and swing phase clearance, prerequisites for normal ambulation, often are lost in the gait of children with cerebral palsy. Lengthening of the hamstrings usually will improve stance-phase knee extension but will not greatly alter swing-phase knee flexion. This paper presents the outcome of transfer of the distal end of the rectus femoris in conjunction with hamstrings lengthening in 37 knees, and compares it with a control group of 24 knees in which only hamstrings lengthening was done. In the first group swing-phase knee flexion was improved by 16.0 +/- 14.4 degrees, compared to 9.5 +/- 7.5 degrees in the control group, and residual knee flexion in stance was reduced to 8.9 +/- 8.1 degrees, compared to 15.1 +/- 13.8 degrees in the controls. Poor outcome in the transfer-plus-lengthening group was associated mainly with foot rotation in excess of 8 degrees internally or externally, or postoperative knee flexion in stance. Criteria for selection of cases and methods of improving surgical outcome are discussed.

Adolescent↗
PubMed1987

Selective tarsal arthrodesis: an in vitro analysis of the effect on foot motion.

Five different intertarsal arthrodeses were simulated in 15 fresh cadaver feet/ankles utilizing external fixation. Pin placement was verified radiographically. Range of motion measurements were performed before pin placement, after pin placement, and after simulated arthrodesis. The deficit in foot motion created by selected limited intertarsal fusions was then measured. The prearthrodesis range of motion measurements were found to be dorsiflexion (DF), 27 degrees; plantarflexion (PF), 57 degrees; total inversion (INVT), 29 degrees; eversion total (EVT), 22 degrees; hindfoot varus (VRH), 16 degrees; hindfoot valgus (VLH), 12 degrees. The deficits in motion after arthrodesis were as follows. Ankle (tibiotalar): DF, 50.7%; PF, 70.3%; INVT, 8.7%; EVT, 9.4%; VRH, 34.6%; VLH, 27.8%. Hindfoot arthrodesis (Tibiotalar calcaneal): DF, 53%; PF, 71.3%; INVT, 49.5%; EVT, 47.6%, VRH, 100%; VLH, 100%. Pantalar (Tibotalar calcaneal cuboid navicular): DF, 62.8%; PF, 82.2%; INVT, 71.7%; EVT, 67.4%; VRH, 100%; VLH, 100%. Triple (Talocalcaneal cuboid navicular): DF, 12.5%; PF, 15.5%; INVT, 50%; EVT, 51.4%; VRH, 60.5%; VLH, 60.5%. Total tarsal arthrodesis: DF, 78.5%; PF, 90.2%, INVT, 87.5%; EVT, 83.6%; VRH, 100%; VLH, 100%.

Ankle Joint↗
PubMed1987

Contractures. A historical perspective.

Orthopedic history vividly documents the continuing battle between restoring tissue stability and preserving functional mobility. Prolonged and uninterrupted rest, popularized by Hilton and Thomas, but promoted by many before them and subsequently continued by Jones, Orr, and others, assures healing. Contractures that permanently limit function are not an uncommon consequence. Hippocrates, Hunter, Lucas-Championniere, and David advocated judicious motion. Timing and the interpretation of the patient's pathologic state have proved to be the critical criteria. Modern antibiotics, antiinflammatory medications, acute surgical repair, and techniques that combine stability and early motion provide today's orthopedic surgeons' great versatility and capability. Despite these advantages the threat of contractures remains. The dictum "rest until healed" persists. Physiologic posturing of inflamed or swollen joints to minimize tissue strain introduces resting positions of 15 degrees plantar flexion at the ankle, and 30 degrees flexion at the knee and hip. These will be perpetuated by contractures if not actively counteracted by timely mobilizing procedures. Each of these joint positions is a serious deterrent to walking without stressful substitutive posturing, and the patient's ability to function is impaired.

Contracture↗
PubMed1987

Surgical treatment of displaced olecranon fractures by tension band wiring technique.

Forty-five displaced olecranon fractures including 14 accompanying dislocated radial heads and seven radial head fractures were treated over a 13-year period by the tension band wiring technique. The use of supplemental internal fixation when necessary allows excellent results with the use of this technique, even in the presence of severe comminution or radial head dislocation. Primary silicone radial head implants fractured in all three patients in which they were used, necessitating repeat surgery in two patients to date. While loss of motion in terminal extension was a common aftermath of displaced olecranon fracture (59%), it was usually minor and functionally insignificant. True Kirschner-wire migration was not a common problem and can probably be eliminated by proper technique. The presence of gaps in the intraarticular surface of the semilunar notch of the ulna produced no ill effects and was compatible with excellent results. If only those cases with isolated olecranon fractures in this series are considered, there were good and excellent results in 29 of 30 cases (97%). Excision of the olecranon fragment(s) should be reserved for those cases when anatomic restoration cannot be achieved with internal fixation.

Adolescent↗
PubMed1987

The energy cost of walking with arthritis of the hip and knee.

The physiologic energy expenditure of walking was measured in patients with severe arthritis. Nine patients were tested following Girdlestone hip resection arthroplasty, six patients prior to total knee arthroplasty (TKA) for unilateral osteoarthritis of the knee, and 49 rheumatoid arthritis patients prior to unilateral TKA; 27 were retested after operation. The results were compared with previously published pre- and postoperative data for total hip arthroplasty (THA) following primary osteoarthritis. There were severe energetic penalties caused by rheumatoid or osteoarthritis involving the hip or knee or following Girdlestone arthroplasty. Walking speed was severely reduced in all groups (range, 33-46 m/minute). The rate of oxygen consumption was not significantly greater than the mean rate of oxygen uptake for normal subjects; however, the oxygen cost per meter travelled was elevated because of the slow walking speed. The heart rate was significantly elevated in all patient groups. The elevated cardiac response can be accounted for on the basis of deconditioning resulting from the patients' pain, limited ambulatory activities, and the systemic effects of rheumatoid disease. In addition, the elevated cardiac response may be caused by added physical exertion by the arms in patients on crutches or walkers. The improvements in speed and energy cost were the same for the group of rheumatoid patients tested after unilateral TKA as in the group of patients tested before and after THA. The clinician can anticipate the same magnitude of improvement from surgery in a rheumatoid patient as in an osteoarthritis patient if the primary joint disease is restricted to a single joint.

Arthritis, Rheumatoid↗
PubMed1986

Vitamin B12 neuropathy is not due to failure to methylate myelin basic protein.

It has been proposed that the biochemical lesion in subacute combined degeneration of the cord due to vitamin B12 deficiency, is impaired methylation of residue 107 (arginine) in myelin basic protein. We have examined myelin basic protein in brains of rats in which vitamin B12 was inactivated by exposure to nitrous oxide for up to 7 days. In addition brains of fruit bats in which vitamin B12 neuropathy had been produced by feeding washed, and hence vitamin B12-free fruit, were examined. There was no difference in the methylation of arginine 107 in myelin basic protein in these animals as compared to healthy control animals. Rats given an inhibitor of transmethylation reactions (cycloleucine) showed the expected fall in methylation of myelin basic protein.

Animals↗
PubMed1986

Resection arthroplasty following infected total hip replacement arthroplasty.

Thirty-nine patients with 41 hips with resection arthroplasty for infected total hip replacement arthroplasty were evaluated for functional level and factors that contribute to that level. Eighty-three percent were either minimal community ambulators or nonambulators, and only two patients walked without assistive devices. At last follow-up, 93% of the patients had pain in their hips. The best function was obtained in patients with a healed wound and heterotopic ossification. The worst functional result was in patients with chronic drainage. Fifteen of the patients with resection arthroplasties had foot-switch studies to determine gait velocity and single-limb stance time. Ten patients also had oxygen consumption studies performed. The average gait velocity was 35 m/minute (41% of normal). The average oxygen consumption was 0.41 ml/gm (264% normal) with an average heart rate of 121. The energy consumption was greater than that recorded in patients with above-knee amputation.

Adult↗
PubMed1986

Electromyography and motion analysis of the upper extremity in sports.

This article reviews the results of studies using electromyographic recordings to determine muscle function during athletic activities. Electromyographic recordings were synchronized with high-speed film to provide information on shoulder muscle firing patterns during baseball pitching, swimming, tennis, and golf. The information obtained about the contributions of specific muscles during these activities may be useful in developing effective injury prevention and rehabilitation strategies.

Baseball↗
PubMed1986

Predictive value of manual muscle testing and gait analysis in normal ankles by dynamic electromyography.

Eight muscles about the ankle of seven normal subjects were assessed by electromyography (EMG) during manual muscle testing (MMT) and walking. Three strength levels (normal, fair, trace) and three gait velocities (free, fast, slow) were tested. The muscles studied included the gastrocnemius, soleus, posterior tibialis, flexor digitorum longus, flexor hallucis longus, anterior tibialis, extensor digitorum longus, and extensor hallucis longus. Relative intensity of muscle action was quantitated visually (using an eight-point scale based on amplitude and density of the signal). The data showed that EMG activity increased directly as more muscle force was required during the different manual muscle test levels and increased walking speeds. No MMT isolated activity to the specific muscle though being tested. Instead, there always was a synergistic response. Both the gastrocnemius and soleus contributed significantly to plantarflexion regardless of knee position. The intensity of muscle action during walking related to the manual muscle test grades. Walking at the normal free velocity (meters/min) required fair (grade 3) muscle action. During slow gait the muscle functioned at a poor (grade 2) level. Fast walking necessitated muscle action midway between fair and normal, which was interpreted as good (grade 4).

Ankle↗
PubMed1985

Effect of cobalamin inactivation on folate-dependent transformylases involved in purine synthesis in rats.

N2O oxidizes and inactivates cob[I]alamin, and animals exposed in this way serve as models for cobalamin 'deficiency'. Such animals show a fall in activity of glycinamide ribotide transformylase and a rise in that of 5-amino-4-imidazolecarboxamide ribotide transformylase. The fall in glycinamide ribotide transformylase activity was prevented by parenteral 5'-methylthioadenosine derived from methionine. Methylthioadenosine in turn is converted into formate. Activity of glycinamide ribotide transformylase recovers after 7 days despite continued N2O inhalation, and this is probably related to restoration of methionine synthesis by induction of betaine:homocysteine transmethylase.

Acyltransferases↗
PubMed1985

Folate polyglutamate synthetase activity in the cobalamin-inactivated rat.

Exposure to N2O inactivates cob[I]alamin and interferes with the activity of methionine synthetase, of which cob[I]alamin is a coenzyme. Less directly, it stops the formation of folate polyglutamate from tetrahydrofolates. Studies on the activity of folate polyglutamate synthetase in rat liver in vivo were carried out. The synthetase activity increased after exposure to N2O for up to 48 h, but longer exposure was accompanied by a return of activity to baseline values. The rise in synthetase activity was prevented by supplying methionine, 5'-methylthioadenosine or 5-formyltetrahydrofolate. The fall in folate polyglutamate synthetase activity after 48 h was accompanied by a restoration of hepatic synthesis of folate polyglutamate despite continuation of N2O exposure.

Amide Synthases↗
PubMed1985

Induction of IgA-specific suppressor activity in human T-lymphocyte cultures.

Cell-free supernatants of human circulating T-lymphocyte cultures incubated with secretory IgA (S-IgA) specifically suppressed both spontaneous IgA synthesis by B lymphocytes isolated from allergic individuals and pokeweek mitogen-induced IgA secretion by peripheral blood mononuclear cells. Cell-free supernatants of T-cell cultures incubated with IgE had no effect on IgA, IgG, or IgM synthesis. Hence, it is concluded that upon incubation with S-IgA, but not with another Ig class, T lymphocytes release IgA-specific suppressor factors.

Antibody Specificity↗
PubMed1985

Surreptitious warfarin ingestion.

Munchausen by proxy has been reported involving children who have been given various drugs or toxins. In addition, there is a body of adult literature regarding covert anticoagulant ingestion. This is a case of an 11-month-old female who appears to combine features of both of these syndromes. This child presented with an acute left hemorrhagic otitis media. The physical examination was unremarkable except for the following: weight, fifth percentile; left external auditory canal filled with blood with the right external canal and tympanic membrane being normal; and several scattered 1 X 2 cm firm, movable, nontender, purple nodules on extremities, chest and forehead. The coagulation studies were consistent with Vitamin K deficiency secondary to anticoagulant ingestion. A serum warfarin study confirmed our suspicions. The mother was noted to have a dependent relationship with her child and characteristics of those involved in Munchausen by proxy: falsifying information and thwarting medical assessment. In addition, she displayed some of the characteristics found commonly in anticoagulant malingerers. She was depressed, with limited medical knowledge, and had access to warfarin. The mother was admitted for inpatient psychiatric care and the patient placed with an extended family member. This case report describes the use of an anticoagulant to induce illness in a child by a psychologically ill mother. This form of child abuse must be considered in the differential diagnoses of hemorrhagic disorders.

Adult↗
PubMed1985

Rising from a chair. Influence of age and chair design.

We studied the effect of age on the act of rising from a standard armchair in a younger (means = 24 years) and an older (means = 75 years) group of healthy adult women. Rising from a standard armchair and an armchair specially designed for comfort in sitting of the elderly was studied in the older group to determine the influence of the special chair. We used electrogoniometry, EMG, and videotape analysis to record the activity for both groups. The older group placed their feet farther back and showed greater vastus lateralis muscle activity than did the younger group to rise from the standard chair. These results suggest that rising from the standard chair was more difficult for the older than for the younger group. In the special chair, the older subjects showed even more vastus lateralis muscle activity, greater knee flexion, and greater trunk forward lean. Rising from the special chair, therefore, appeared to be more difficult than rising from a standard chair; this finding suggests that both comfort and function must be considered in chair selection for certain groups.

Adult↗
PubMed1985

Walking patterns of healthy subjects wearing rocker shoes.

We compared walking in rocker shoes with walking in athletic shoes at free and fast velocities in 15 healthy women who were between the ages of 21 and 30 years. Footswitches, electrogoniometers, surface electromyograms, and a force plate were used for data collection. No significant differences were found in velocity, cadence, gait-cycle duration, single-limb support, or swing-stance ratios in free and fast walking. Double-limb support was decreased by 9% in the rocker shoes in free walking. The ankle range of motion showed accommodation of the foot to the 8.5 degrees of plantar flexion built into the rocker shoes. Electromyographic responses appeared to be similar regardless of shoes or cadence.

Adult↗