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Biomedical subjects

R A Mann

Publications and source records attributed to R A Mann.

118 records · Page 7Linked to original sources
PubMed1971

The effects of receptive language training on articulation.

The present study attempted to assess one condition of language exposure that might be operative in a normal environment, and experimentally determine its relevance to the acquisition of productive speech. The results demonstrated that the development of receptive language skills can be functionally related to productive speech. Specifically, the data indicated that exposure to words that have stimulus control over a subject's nonverbal pointing behavior can facilitate later articulation of those same words. Thus, this study draws attention to the fact that at least some classes of operants, in this case verbal, can be affected not only by their consequences, but by not obviously related antecedent events as well.

Journal Article↗
PubMedDate not supplied

Modulation of murine in vitro immune response by verapamil (V).

Functionally distinct lymphocyte subsets differ with regard to necessary activation signals. In selected circumstances lymphocyte activation has been shown to be critically dependent upon transcellular calcium influx. Whether calcium plays a central role in the activation of all lymphocytes remains to be determined. The effect of the calcium channel blocker verapamil on the induction of murine cytotoxic T lymphocytes (CTL), suppressor cells, T helper cells, and B cells was investigated. Verapamil (V) was found to inhibit the induction of cytotoxic effector cells. V acted primarily on the afferent limb of this immune response, was synergistic with cyclosporin A (CsA), and its effects could be largely reversed by the addition of exogenous helper factors. V also inhibited B cell proliferation in response to anti-mouse IgM in the presence of 2-mercaptoethanol, but in the absence of cognate or non-cognate T cell help. In contrast to this, V did not inhibit the activation of cells capable of inducing B cell proliferation nor did it inhibit the induction of suppressor cells. The selective suppression of V is discussed in terms of activation requirements of CTL, suppressor cells and helper cell subsets.

Animals↗
PubMedDate not supplied

Biomechanics of walking, running, and sprinting.

A biomechanical study of 13 runners which consisted of 2 male sprinters, 5 experienced joggers, and 6 elite long-distance runners were studied. We obtained hip, knee, and ankle joints motions in the sagittal plane and electromyographic data from specific muscle groups. As the speed of gait increased, the length of stance phase progressively decreased from 62% for walking to 31% for running and to 22% for sprinting. The sagittal plane motion increased as the speed of gait increased. Generally speaking, the body lowers its center of gravity with the increased speed by increasing flexion of the hips and knees and magnifying dorsiflexion at the ankle joint. Electromyographic activity about the knee demonstrated increased activity in the quadricep muscle group and hamstring group with increased speed. Muscle function about the ankle joint demonstrated that the posterior calf musculature which normally functions during the midstance phase in walking became a late swing phase muscle and was active through the first 80% of stance phase, as compared to 15% in walking. Beside the changes in the electromyographic activity of the muscles, the anterior compartment muscles of the calf undergo a concentric contracture at the time of initial floor contact during running and sprinting but undergo an eccentric contraction during walking.

Ankle Joint↗
PubMedDate not supplied

Comparative electromyography of the lower extremity in jogging, running, and sprinting.

An electromyographic study of the lower extremity muscles was undertaken in order to compare jogging, running, and sprinting. The study demonstrated that as the speed of gait increased, the support phase decreased, from 620 msec for walking to 260 msec for jogging to 220 msec for running to 140 msec for sprinting. The electromyographic data demonstrated that all muscle groups except the hip flexor and adductor longus were active during foot descent, floor contact, and midsupport. There was absence of muscle function during the late toe-off phase except that demonstrated by the adductor longus and the abdominal muscles during sprinting. The main muscle group that appears to increase the speed of gait is that of the hip flexors, which is closely linked to the knee extensors in order to propel the body forward in the line of progression. There was little or no activity in the gastrocnemius or in the intrinsic muscles of the foot about the time of toe-off, leading the authors to conclude that push-off per se does not appear to occur.

Adult↗
PubMedDate not supplied

Interdigital neuroma--a critical clinical analysis.

A retrospective study of 56 patients upon whom 76 interdigital neuromas were excised was carefully evaluated. There were 53 females and 3 males, with an average age of 55 years. The main preoperative symptom was pain in the plantar aspect of the foot which was increased by walking and relieved by rest. The main preoperative physical finding was that of tenderness in the involved interspace. There were an equal number of interdigital neuromas removed from the second and third interspace. Postoperatively 65% of patients still noted some local plantar tenderness, and 68% noted numbness in the interspace. Postoperatively 80% of the patients were subjectively improved.

Adult↗
PubMedDate not supplied

The function of the toes in walking, jogging and running.

The foot has been studied in walking, running and jogging using high speed cinema photography in the laboratory for gait analysis in the Shriner's Hospital for Crippled Children, San Francisco. During running, as well as in walking, the extrinsic toe flexors restrain progression of the tibia. The extrinsic extensors accelerate the tibia over the fixed foot. The intrinsic toe muscles function from mid-stance to lift-off when the subject runs on his toes. In sprinting, the intrinsics are active throughout the weight-bearing phase.

Gait↗
PubMedDate not supplied

Hallux rigidus: A review of the literature and a method of treatment.

Twenty patients with hallux rigidus were evaluated following cheilectomy. The surgical procedure involved resection of proliferative bone at the metatarsophalangeal joint to allow at least 45 degrees of passive dorsiflexion. The follow-up ranged from 7 months to 156 months. Postoperatively, there was minimal progression of the degenrative process. Subjectively, there was uniform patient satisfaction with the procedure.

Adult↗
PubMedDate not supplied

Surgical implications of biomechanics of the foot and ankle.

Because of the nature of the alignment the joints of the lower extremity, any significant loss of alignment or function will place increased stress on the remaining joints. An ankle arthrodesis must be carefully aligned into slight valgus and neutral dorsiflexion, plantar flexion and the same degree of external rotation as the opposite leg. A subtalar arthrodesis should be aligned in 5 degrees of valgus. The forefoot should be placed in a plantigrade position when arthrodesis of the subtalar or transverse tarsal joint is contemplated. The stability of the longitudinal arch and forefoot is dependent in part upon the integrity of the metatarsophalangeal joints and as such, neither a resection of the metatarsal head or base of the phalanx should be carried out except under extreme disease states, such as rheumatoid arthritis. If an arthrodesis of the first metatarsophalangeal joint is contemplated, it is important that the joint be aligned in approximately 5 degrees to 10 degrees of valgus and 15 degrees to 25 degrees of dorsiflexion, depending upon the heel height that the patient anticipates using. When considering a tendon transfer about the foot and ankle, the relationship of the tendon to the axes of the subtalar and ankle joint requires special consideration.

Adult↗