Graduation date: 2005

The aim of this study was to determine the pre- and post-plantar force differences of athletes competing in an ultra-endurance event. The study was exploratory and quasi-experimental in nature and utilized a quantitative approach. A Quasi-experimental, one group pretest, posttest design was used. The study involved 84 participants selected by means of convenient sampling from a total of 1552 participants. The equipment used for data collection was the RS Footscan®, stadiometer and a weight scale. Differences between the plantar forces before and after the competition were significant for the sample group, indicating higher forces before the competition (t = -3.62, p = 0.001, d = 0.40). Gender, and novice and expert groupings had no significant effect on the plantar forces (t = 1.43, p = 0.155 and t = 0.21, p = 0.837) respectively. Gender groups had large significant differences between the left and right forefoot (t = 3.90, p = 0.000) and the heel (t = 3.54, p = 0.001), before the competition, but this difference was reduced after the competition from large to moderate significance for the forefoot and the heel (t = 2.84, p = 0.006 and t = 2.99 and p = 0.004) respectively. Lower forces after the ultra-endurance event may indicate compensation due to overuse; with less muscle contraction to control foot roll over for force distribution. Favouring of the right foot for weight bearing changed after the event with smaller differences, which could indicate increase loading of the left feet, which may result in injury. The number of females included in this study was relatively few and therefore the effect of gender in respect of plantar foot force exerted should be interpreted with caution. The novices recorded higher forces in the forefoot, after the competition. Similar results were found in other studies that reported increased pressures under the forefoot after long distance running. The latter findings may suggest that novices have a higher chance for overuse injury.

Purpose: To highlight the histopathological characteristics of the skin in congenital clubfoot and correlate the clinical findings in clubfoot with the changes in the dermal layers. Materials and methods: One hundred skin specimens, from 77 infants (6 to 12 months), were studied between 2004 and 2008. Using the Pirani scoring system, the clinical severity was recorded. The mobility of the skin and the correctability of the medial ray were assessed clinically. A skin specimen (1cm x 1mm) was taken from the medial side of the foot at surgery following failed plaster treatment. The layers were studied under light microscopy. The thickness of the dermis and the histopathological features of clubfoot skin were compared with 10 normal skin specimens. Results: The dermis of clubfoot skin showed significant fibrosis with thick bundles of collagen fibres (P = .001) on Haematoxylin and Eosin staining (H&E). The dermal thickness ranged between 1.0mm and 5.2mm in clubfoot skin, compared with controls (0.64-1.28mm). Fibrosis extended into the subcutis in a septolobular fashion in 95% of the cases. Significant atrophy of eccrine glands was seen in 98% (P = .001). Hair follicles were absent in 78%. The elastic fibres of clubfoot skin, stained with Elastic van Gieson staining (EVG), showed hypertrophy in varying degrees in all skin specimens. They were fragmented, with loss of their parallel arrangement. There was no significant inflammatory reaction in the dermis. The Pirani score was significantly increased (mean 7.8). Discussion: Fibrosis and thickening of the dermis were the most significant histopathological features of the clubfoot skin. The elastic fibres were also abnormal. There was atrophy of the skin appendages due to the fibrosis. There was a strong correlation between the Pirani score and the severity of the deformity(P 0.016). The cases with poor outcome had a higher score than those with a satisfactory outcome.Lack of a significant inflammatory reaction suggests that neither the serial manipulations of the foot, nor the repeated plaster cast changes, were responsible for the dermal fibrosis, which is probably present from birth and contributes to the deformity. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2012.

The British Columbia [B.C.] Polydactyly study was designed to investigate the occurrence of Polydactyly in the B.C. population. Polydactylous infants born in the province in the years 1964 - 1967 were ascertained principally through the Registry for Handicapped Children and Adults; additional cases were found-through disease indexes of B.C. hospitals and through referrals from medical personnel. Data on the probands were obtained by family interviews and review of various medical records. Information compiled for a case included: sex of proband, racial background, parental age, parity of mother, notes on the pregnancy, description of accessory digits, genetic family history, and nature of additional congenital anomalies when rpresent. Incidence of Polydactyly in B.C. for 1964 - 1967 was 1.02 per 1,000 live births. This figure includes patients with multiple congenital anomalies. Of the four years covered by the study, 1966 had the highest incidence (1.35), a year in which a seemingly disproportionate number of ulnar cases occurred. Ninety-five males and 43 females, a sex ratio of approximately 2:1, presented the following types of duplication: radial (31), tibial (6), ulnar (54), fibular (24) and ulnar and fibular (16). It is proposed that cases with both ulnar and fibular accessory digits and cases with ulnar or fibular accessory digits in whose family both ulnar and fibular duplication occur present ulnar-fibular type Polydactyly. Based on cases unassociated with multiple congenital anomalies, specific types of Polydactyly had the following incidences: radial 0.20; tibial, 0.04; polysyndactyly, 0.01; ulnar, 0.32; fibular, 0.16; and ulnar-fibular, 0.09. Genetic histories indicate in 32 families out of 138 there is another individual with Polydactyly. For specific types of Polydactyly the following proportion of cases without multiple congenital anomalies had a positive family history: radial, 5 - 19 %; tibial, 0 %; ulnar, 29 %• fibular, 25 and ulnar-fibular, 73 f°~ Polygenic inheritance of ulnar and of fibular types of Polydactyly is suggested by the finding that the percentage of affected sibs is greater when there is a history of Polydactyly in previous generations (approximately 6.6 %) than for probands with a negative history (1.2 %). The number of affected sibs of the probands (3/107) is in agreement with the number which would be expected for a polygenic trait. Data for ulnar-fibular Polydactyly is more compatible with dominant inheritance with reduced penetrance among females. Fifty percent of the offspring of polydactylous males were affected; a smaller percentage of the children of affected mothers were polydactylous (27.7 %). Nonpenetrance of the Polydactyly gene(s) would seem to be fairly common among females since unaffected mothers are known to pass the trait to their children whereas such an occurrence is unknown for males. . Among ulnar-fibular cases with no history of accessory digits in previous generations, 17.4 % of the sibs were polydactylous. Major congenital anomaly was noted in 33 probands and occurs approximately 3½ times more frequently among the polydactylous infants than the general population. Multiple major anomalies are approximately 25 times more frequent. A polydactylous child found to have one major malformation is twice as likely to have additional major anomalies than a child with one major anomaly who has the normal number of digits. Multiple congenital anomalies were most commonly seen with ulnar-fibular Polydactyly. This may reflect the fact that ulnar-fibular duplication is the type most commonly seen as a feature of various syndromes. In addition to the B.C. findings, literature on Polydactyly has been reviewed. Included are: data on the incidence of Polydactyly in other populations, description of different types of duplication, hypotheses regarding the inheritance of accessory digits, tabulation of the types of Polydactyly seen in various syndromes, and discussion of the morphogenesis of accessory digits in relation to limb embryogenesis. / Medicine, Faculty of / Medical Genetics, Department of / Graduate

This paper has been undertaken, first, to contribute several more cases of various congenital anomalies to the literature on human genetics, and, second, by an analysis of the genealogies, to determine the possible modes of transmission of these anomalies.

Diabetes can affect the structure and function of the foot, resulting in severe limitation of mobility and reduction of life expectancy. Early warning signs include limited joint mobility (LJM), soft tissue changes, high plantar pressure (HPP), high pressure time integrals (P/TI) and plantar callus. These abnormalities were examined in 216 young people with diabetes and 57 controls. The fingers, toes, ankle subtalar and first metatarsophalangeal joints shows reduced motion and the plantar aponeurosis was thicker in diabetic subjects. Skin thickness was the same for diabetic and control subjects. LJM in the feet was more common in males and older subjects. Subtalar and finger LJM was associated with early sensory nerve changes and finger LJM was associated with retinopathy and higher HbAtc. Thicker plantar aponeurosis was associated with male gander and larger feet. High peak pressure, high P/TI and callus were no more common in diabetic subjects than controls. However, high P/TI and callus were associated with early sensory nerve changes in young people with diabetes. Diabetic subjects with callus were significantly older than those without callus. Those with HPP had higher body mass index and less motion at the first MTP joints than those without HPP. Although plantar callus, HPP and high P/TI were no more common in young people with diabetes these abnormailities may be complicated by diabetes. Cushioning, custom orthoses or both in combination significantly reduced peak pressure and P/TI in diabetic subjects. / Doctor of Philosophy (PhD)

published_or_final_version / abstract / toc / Orthopaedics and Traumatology / Master / Master of Philosophy