Soft-tissue vibration and damping response to footwear changes across a wide range of anthropometrics in running.

Different factors were shown to alter the vibration characteristics of soft-tissue compartments during running. Changing pre-heel strike muscle activation or changing footwear conditions represents two possibilities to influence the vibration response via frequency shift or altered damping. Associated with the study of muscle pre-tuning is the difficulty in quantifying clean experimental data for the acceleration of soft-tissue compartments and muscle activities in heterogeneous populations. The purpose of this study was to determine the vibration and pre-tuning response to footwear across a wide range of participants during running and establish and describe groups formed according to the damping coefficient. 32 subjects were used for further analysis. The subjects ran at a self-selected speed (5 min) on a treadmill in two different shoes (soft & hard), while soft-tissue accelerations and muscle activation at the gastrocnemius medialis were quantified. Damping coefficients, total muscle intensity and dominant vibration frequencies were determined. Anthropometrics and skinfold measurements of the lower limbs were obtained. According to the damping coefficient response to the footwear intervention, three groups were formed, with most runners (n = 20) showing less damping in the hard shoe. Total muscle intensity, anthropometrics, and dominant vibration frequency across footwear were not different for these three groups. Most runners (84.4%) used the strategy of adjusting the damping coefficients significantly when switching footwear. Despite damping being the preferred adjustment to changes in footwear, muscle pre-tuning might not be the only mechanism to influence damping as previously suggested. Future studies should focus on the subject-specific composition of soft-tissue compartments to elucidate their contribution to vibrations.

Shorter heels are linked with greater elastic energy storage in the Achilles tendon.

Previous research suggests that the moment arm of the m. triceps surae tendon (i.e., Achilles tendon), is positively correlated with the energetic cost of running. This relationship is derived from a model which predicts that shorter ankle moment arms place larger loads on the Achilles tendon, which should result in a greater amount of elastic energy storage and return. However, previous research has not empirically tested this assumed relationship. We test this hypothesis using an inverse dynamics approach in human subjects (n = 24) at speeds ranging from walking to sprinting. The spring function of the Achilles tendon was evaluated using specific net work, a metric of mechanical energy production versus absorption at a limb joint. We also combined kinematic and morphological data to directly estimate tendon stress and elastic energy storage. We find that moment arm length significantly determines the spring-like behavior of the Achilles tendon, as well as estimates of mass-specific tendon stress and elastic energy storage at running and sprinting speeds. Our results provide support for the relationship between short Achilles tendon moment arms and increased elastic energy storage, providing an empirical mechanical rationale for previous studies demonstrating a relationship between calcaneal length and running economy. We also demonstrate that speed and kinematics moderate tendon performance, suggesting a complex relationship between lower limb geometry and foot strike pattern.

Reliability testing of the heel marker in three-dimensional gait analysis.

INTRODUCTION: In three-dimensional gait analysis, anatomical axes are defined by and therefore sensitive to marker placement. Previous analysis of the Oxford Foot Model (OFM) has suggested that the axes of the hindfoot are most sensitive to marker placement on the posterior aspect of the heel. Since other multi-segment foot models also use a similar marker, it is important to find methods to place this as accurately as possible. The aim of this pilot study was to test two different 'jigs' (anatomical alignment devices) against eyeball marker placement to improve reliability of heel marker placement and calculation of hindfoot angles using the OFM. METHODS: Two jigs were designed using three-dimensional printing: a ratio caliper and heel mould. OFM kinematics were collected for ten healthy adults; intra-tester and inter-tester repeatability of hindfoot marker placement were assessed using both an experienced and inexperienced gait analyst for 5 clinically relevant variables. RESULTS: For 3 out of 5 variables the intra-tester and inter-tester variability was below 2 degrees for all methods of marker placement. The ratio caliper had the lowest intra-tester variability for the experienced gait analyst in all 5 variables and for the inexperienced gait analyst in 4 out of 5 variables. However for inter-tester variability, the ratio caliper was only lower than the eyeball method in 2 out of the 5 variables. The mould produced the worst results for 3 of the 5 variables, and was particularly prone to variability when assessing average hindfoot rotation, making it the least reliable method overall. CONCLUSIONS: The use of the ratio caliper may improve intra-tester variability, but does not seem superior to the eyeball method of marker placement for inter-tester variability. The use of a heel mould is discouraged.

The relationship of heel fat pad thickness with age and physiques in Japanese.

BACKGROUND: In understanding the onset factors associated with Plantar heel pain and the structure of heel fat pad, measuring its thickness is the most basic frequently reported evaluation. This study aimed to determine changes to heel fat pad thickness associated with age and gender and the relationship between heel fat pad thickness, age, and physique in Japanese. METHODS: This study was carried out in 1126 healthy individuals between the ages of 1 and 96 years. Participants were categorized according to age. Heel fat pad thickness was measured with an ultrasonography device using a linear ultrasonography probe. FINDINGS: Heel fat pad tends to become thicker from ages 1-5 to 30-44 years and thinner from ages 30-44 to 80-96 years. Heel fat pad thickness in males and females was similar within each group, and males had higher heel fat pad thickness than females of corresponding ages. Heel fat pad thickness of males had a good correlation with height and body mass. Moreover, male heel fat pad thickness had a fair correlation with age. Heel fat pad thickness of females had a moderate correlation with height and body mass and a fair correlation with age. INTERPRETATION: Heel fat pad thickness became thicker from ages 1-5 to 30-44 years and thinner from ages 30-44 to 80-96 years. Females had a lower heel fat pad thickness than males of corresponding ages. This result suggests that higher heel fat pad thickness in males is related to body mass and height.

Mechanics of heel-strike plantigrady in African apes.

The initiation of a walking step with a heel strike is a defining characteristic of humans and great apes but is rarely found in other mammals. Despite the considerable importance of heel strike to an understanding of human locomotor evolution, no one has explicitly tested the fundamental mechanical question of why great apes use a heel strike. In this report, we test two hypotheses (1) that heel strike is a function of hip protraction and/or knee extension and (2) that short-legged apes with a midfoot that dorsiflexes at heel lift and long digits for whom digitigrady is not an option use heel-strike plantigrady. This strategy increases hip translation while potentially moderating the cost of redirecting the center of mass ('collisional costs') during stance via rollover along the full foot from the heel to toes. We quantified hind limb kinematics and relative hip translation in ten species of primates, including lemurs, terrestrial and arboreal monkeys, chimpanzees, and gorillas. Chimpanzees and gorillas walked with relatively extended knees but only with moderately protracted hips or hind limbs, partially rejecting the first hypothesis. Nonetheless, chimpanzees attained relative hip translations comparable with those of digitigrade primates. Heel-strike plantigrady may be a natural result of a need for increased hip translations when forelimbs are relatively long and digitigrady is morphologically restricted. In addition, foot rollover from the heel to toe in large, short-legged apes may reduce energetic costs of redirecting the center of mass at the step-to-step transition as it appears to do in humans. Heel strike appears to have been an important mechanism for increasing hip translation, and possibly reducing energetic costs, in early hominins and was fundamental to the evolution of the modern human foot and human bipedalism.

[Anatomical calcaneal external fixator self-designed according to the morphology of heel].

OBJECTIVE: The anatomical calcaneal external fixator was designed by measuring and calculating the morphological data of the heel. METHODS: A total of 100 normal people were randomly selected to obtain 200 hind foot data, including 45 males and 55 females, with an average age of 43.9 years (range, 19-67 years). According to the principles of human engineering and local anatomy, the morphological data of the heel in the weight-bearing standing position and supine position were measured with the direct measurement mode. The heel length, heel width, heel height, medial ankle height, lateral ankle height, and calcaneal pitch angle (CPA) were measured by vernier calipers and ulnar markers in weight-bearing standing position, and the gender groups and left and right foot groups were compared; the shape of the hind foot in the supine position was measured by three-dimensional (3D) dot matrix inverse model method. According to the stereoscopic data of the comprehensive anatomical morphology of the heel, the anatomical calcaneal external fixator was designed with AutoCAD 2019 and other 3D industrial design softwares. RESULTS: The measurements of shoe size, heel length, heel width, heel height, medial ankle height, lateral ankle height, and CPA in male were significantly higher than those in female ( P<0.05). There was no significant difference between the left and right feet in the other indexes except that the height of the medial malleolus of the left foot was significantly lower than that of the right foot ( t=-2.827, P=0.005). The measurement of 3D dot matrix inverse model in supine position showed that the heel part was non-circular arc edge, and many groups of arc edges fluctuate in a limited range. Based on the above data, an anatomical calcaneal external fixator was designed, which could fit the anatomic radian in theory, so as to be flexible in configuration. On this basis, the ordinary configuration, compression configuration, and orthodontic configuration were designed to meet the treatment needs of calcaneal fractures in different degrees. The ordinary configuration was suitable for patients with Sanders Ⅰ, ⅡA, and ⅡB calcaneal fractures with no or slight displacement of intra-articular fractures; the ordinary configuration was mainly used for simple fixing. The compression configuration was suitable for patients with Sanders ⅡC, ⅢA, and ⅢB, tongue fractures, and avulsion fractures with severe displacement of intra-articular fractures; the compression configuration used obliquely drawn console wires to fix the displaced bones. The orthodontic configuration was suitable for patients with Sanders ⅢC and Ⅳ calcaneal fractures with severe displacement of intra-articular fractures or severe calcaneal bone defects; the orthodontic configuration was a multi-module design, which took into account the stable fixation of the fracture and the arbitrary adjustment of the joint fixation angle. CONCLUSION: The hind foot is special for morphology, so the external fixator designed based on the vernier caliper measurement method and 3D dot matrix measuring plate measurement method is an anatomical type and its configuration can theoretically meet stable and flexible clinical needs.

The injection site in the tarsal tunnel to minimize neurovascular injury for heel pain: an anatomical study.

INTRODUCTION: The aim of this study was to investigate the location and distribution patterns of neurovascular structures and determine the effective injection point in the tarsal tunnel for heel pain. METHODS: Fifteen adult non-embalmed cadavers with a mean age of 71.5 years were studied. The most inferior point of the medial malleolus of the tibia (MM) and the tuberosity of the calcaneus (TC) were identified before dissection. A line connecting the MM and TC was used as a reference line. The reference point was expressed in absolute distance along the reference line using the MM as the starting point. For measurements using MRI, the depth from the skin was measured to inferior at an interval of 1 cm from the MM. RESULTS: The posterior tibial artery, lateral plantar nerve, and medial plantar nerve were located from 29.0 to 37.3% of the reference line from the MM. The distribution frequencies of the medial calcaneal nerve on the reference line from the MM were 0%, 8.60%, 37.15%, 37.15%, and 17.10%, respectively. The mean depth of the neurovascular structures was 0.3 cm. DISCUSSION: This study recommended an effective injection site from 45.0 to 80.0% of the reference line.

Judging heel height: A new test for proprioception while standing reveals that young hypermobile children perform better than controls.

BACKGROUND: Children with Generalized Joint Hypermobility (GJH) have been reported to have poorer proprioception than children with normal mobility. However, they were usually tested under unloaded conditions and in an age-group in which pain starts to play a role. RESEARCH QUESTION: In contrast, some young children with GJH perform well in motor tasks, suggesting they may have good proprioceptive abilities if assessed more ecologically. METHODS: Children with GJH (Beighton score of  ≥ 5; mean age 8.34 years) were compared to children with a Beighton score of 4 or less. A proprioception test was performed using wedges of different heights to evaluate the ability to judge heel height. A pair of wedges of various heights, was placed under the children's feet at random and they were required to report the higher leg while standing RESULTS: Independent t-test showed that children with GJH performed better (p < 0.01) than controls, suggesting better proprioceptive abilities when assessed under loaded conditions SIGNIFICANCE: Children with GJH do not have inferior proprioception when tested under loaded conditions. The least one can say is that one should be careful in postulating that measuring passive position sense in one particular joint is necessarily the best estimation of proprioception. Body position during standing can be estimated on the basis of knowledge of joint positions (of the ankle in particular in the present test) but also of other information (loading of foot mechanoreceptors for example). In conclusion, the new test may be more suited to evaluate proprioception than the conventional tests, which rely on passive joint position estimation during sitting.

Effects of heel height with backpack loading in young people.

BACKGROUND: There are many intrinsic and extrinsic factors that could affect posture. Two of them are backpack and heel height. The aim of this study is to investigate the immediate static effects on cervical and lumbosacral postural changes to determine the effects of heel and forefoot heights with backpack loading on both vertebral curves and posture. METHODS: Craniovertebral (CVA), pelvic tilt (APT), and ankle joint motion angles were measured from sagittal photographs of 20 university students in a static posture while carrying backpacks. The same measurements were taken and recorded conventional shoes with heel and forefoot heights. Postural analysis software (PAS/SAPO) was used to conduct angle assessments of the photos. RESULTS: Postural angles of the vertebral column on the cervical and lumbosacral regions are changed immediately up to the posterior thoracic load with backpacks in young people. CVA was an average of 52° only shoes and no load condition, while the angle was reduced to 49° with loading. In contrast, an increasing angle with additional heel height and zero heel height in conventional shoes were reported. CVA increased with heights to 53° for the heel and 55° at the forefoot. The average APT angle was 14° only shoes and no load condition, and this angle increased to 18.9° with the 20% BW load. Accordingly for the no load and load conditions, the significant increase in the APT angle was 21° with the 20% BW load with heel height and 23° for the 20% BW load along with forefoot height. The heights provided negative effects on the vertebral posture and ankle angle. CONCLUSIONS: The results of the study indicate that it may not be advisable for young people to wear shoes with high heels and negative heel height by taking into account the risk factors in the body and ankle postural compensation while carrying a backpack.

Effect of heel base area and walking speed on the utilized coefficient of friction during high-heeled walking.

BACKGROUND: The utilized coefficient of friction (uCOF) and the risk of slipping are known to increase as the heel height of shoes increases. The heel base area of shoes can also affect the uCOF. OBJECTIVE: The purpose of this study is to investigate the effect of the heel base area of high heels and walking speed on the uCOF during walking and their interaction effect. METHODS: The walking experiment was conducted at the speed of 1.0 m/s and 1.25 m/s using four 9-cm high heels having different heel areas (narrow, moderate, wide, and wedge heels). RESULTS: The peak uCOF was significantly lower when wearing the wide heels than when wearing the other heels. Wearing the narrow and moderate heels reduced the vertical ground reaction force (GRF) owing to the early timing of the peak anterior-posterior GRF and increased the peak uCOF. As the walking speed became faster, the peak uCOF became greater with more increases by the interaction effect when wearing the narrow and moderate heels than when wearing the wide and wedge heels. CONCLUSIONS: These results imply that wearing narrow high heels should be considered carefully, as the potential for a slip could be high owing to the increase in the peak uCOF. If it is inevitable to wear narrow high heels, it is critical to walk at a slower speed than usual. It is better to wear high heels with a wide heel area, e.g., 3 cm*3 cm, rather than narrow high heels or even wedge heels to reduce the possibility of slipping.

Differences in sprinting performance and kinematics between preadolescent boys who are fore/mid and rear foot strikers.

The purpose of this study was to clarify whether foot strike patterns are associated with different sprint performance and kinematics in preadolescent boys. The study enrolled 24 healthy 10-11-year-old boys in the fifth grade at public elementary schools in Japan. The participants performed the 50-m sprint with maximum effort. Sprint motion was recorded using a high-speed video camera (120 fps) placed in the sagittal plane on the left side of a line drawn at 35-m from the start line. Kinematic variables were calculated based on manually digitized body landmark coordinates. The participants were categorized into two groups according to their foot strike pattern (rearfoot strikers, RF group, n = 12; forefoot or midfoot strikers, FF/MF group, n = 12). The time taken to complete the 50-m sprint in the FF/MF group (9.08±0.52 s) was faster than that in the RF group (9.63±0.51 s). The FF/MF group had greater sprint speed, higher step frequency, and shorter foot contact time than the RF group. Regarding the association between foot strike pattern and sprint kinematics, we found that the RF group had a greater range of knee flexion during the support-leg phase, whereas the FF/MF group had shorter horizontal distance from the heel of the support leg to the centre of mass at the touchdown, greater maximal knee flexion velocity during the swing-leg phase, and higher the maximum hip extension velocity during the support-leg phase. The current results suggested that, in preadolescent boys, forefoot or midfoot strike (rather than rearfoot strike) is effective for obtaining a higher step frequency and sprint speed through greater magnitude of knee flexion and hip extension movement velocities during the swing and support phases, respectively. The current findings will be useful for understanding the characteristics of the development of sprinting performance in preadolescent children.

How type and number of training sessions influence the reliability of palpation.

INTRODUCTION: Accurate and reliable palpation is needed to identify anatomical landmarks as well as to assess motion and dysfunctions. Although different trials suggested that training might increase reliability of palpation, the poor dependability of the examined tests may show the need to review the teaching methods to improve palpatory accuracy? The aims of this study were: METHODS: 82 examiners with different years of experience were enrolled from AIMO institute. Two different type of training sessions were performed (individual and group training). A total of 5 training sessions were performed during 5 weeks and 5 different models with a similar BMI were used. A uni-variated statistical analysis was used to evaluate the main effect of type and number of trainings, a multi-variated analysis was used to verify cross-effects. RESULTS: Overall results show moderate reliability for the correct detection of the position of the heel lift (Random probability being 33%, GT = 58.6% and SIPS = 57.1%, both P-value < 0.001). No difference was shown between the types of training (p-value GT = 0.503, p-value PSIS = 1) and no overall improvement was shown after the first training (P-value(GT) = 0.25, P-value(PSIS) = 0.96). The professional group improved the reliability during the training sessions starting from substantial reliability and ended with an almost perfect reliability (P-value GT = 0.0029, P-Value PSIS<0.001). Whereas the 3rd 4th and 5th showed a decreased performance. CONCLUSIONS: Type of training sessions seems not to influence reliability of palpation accuracy. The improvement of reliability during the training sessions seems to be related to the experience of examiners, which plays an important role in reliability and the learning experience.

Lateralizing Calcaneal Osteotomies and Their Effect on Calcaneal Alignment: A Three-Dimensional Digital Model Analysis.

BACKGROUND: Few authors have directly compared multiple types of lateralizing calcaneal osteotomies (LCOs) in terms of their ability to achieve deformity correction. The aim of this research was to use a digital model of a varus hindfoot to compare 4 different LCOs in terms of deformity correction and amount of tuberosity lateralization required. The authors hypothesis was that osteotomies involving a wedge resection would achieve greater correction with less lateralization. METHODS: A weightbearing computed tomographic scan of a patient with a varus hindfoot deformity was used to construct a 3-dimensional digital model of the hindfoot, preserving weightbearing alignment. Four different LCOs were modeled: a standard oblique osteotomy, a Dwyer osteotomy, a modified Dwyer osteotomy involving lateralization in addition to wedge resection, and a Malerba Z-type osteotomy with wedge resection and lateralization. Incremental corrections were performed with each osteotomy type, and amount of correction was assessed with a vertical hindfoot angle and measurement of the lateral translation of the most inferior aspect of the calcaneus. Calcaneal length and osteotomy contact surface area were also measured. RESULTS: The modified Dwyer osteotomy led to the greatest improvements in the vertical hindfoot angle and lateral translation, followed by the Malerba osteotomy. The standard and Malerba osteotomies allowed the most preservation of calcaneal length; the Malerba and Dwyer osteotomies had the greatest contact surface area. CONCLUSION: LCOs that involve wedge resection as well as lateralization were able to achieve the greatest correction of hindfoot varus. CLINICAL RELEVANCE: For the surgical treatment of cavovarus foot deformities, osteotomies with wedge resection in addition to lateralization enable more powerful correction.

Effect of Gender on Mechanical Properties of the Plantar Fascia and Heel Fat Pad.

BACKGROUND: The purpose of the study was to investigate the plantar fascia and heel fat pad stiffness and thickness parameters in females and compare these values with those of males. METHODS: This study was carried out in 60 healthy sedentary participants (30 female, 30 male) between the ages of 19 and 50 years. Shear wave velocity (SWV) and thickness of the plantar fascia and heel fat pad were measured with an ultrasonography device. RESULTS: Males had a higher plantar fascia ( P = .037) and heel fat pad ( P = .001) thickness compared with females, but SWV of the plantar fascia ( P = .673), heel fat pad microchamber layer ( P = .240), and heel fat pad macrochamber layer ( P = .636) were similar in both groups. Body mass had a strong correlation with the plantar fascia ( r = 0.64, P < .001) and heel fat pad thickness ( r = 0.68, P < .001). Height had a moderate correlation with the plantar fascia ( r = 0.44, P < .001) and heel fat pad thickness ( r = 0.42, P = .001). CONCLUSION: Plantar fascia and heel fat pad stiffness were similar in both genders; however, females had a lower plantar fascia and heel fat pad thickness compared with males. Correlation analysis results suggest that higher plantar fascia and heel fat pad thickness in males may be related to higher body mass and height. LEVELS OF EVIDENCE: Level III: Retrospective comparative study.

Foot Structure and Function in Habitually Barefoot and Shod Adolescents in Kenya.

Habitually barefoot (HB) children from the Kalenjin tribe of Kenya are known for their high physical activity levels. To date, there has been no comprehensive assessment of foot structure and function in these highly active and HB children/adolescents and link with overuse injuries. PURPOSE: The aim of this research is to assess foot structure, foot function, injury and physical activity levels in Kenyan children and adolescents who are HB compared with those who were habitually shod (HS). METHODS: Foot structure, function, injury prevalence, and physical activity levels were studied using two studies with equal numbers of HS and HB. HS and HB children and adolescents were matched for age, sex, and body mass. Foot arch characteristics, foot strength, and lower-limb injury prevalence were investigated in Study 1 (n = 76). Heel bone stiffness, Achilles tendon moment arm length and physical activity levels in Study 2 (n=62). Foot muscle strength was measured using a strength device TKK 3360 and heel bone stiffness by bone ultrasonometry. The moment arm length of the Achilles tendon was estimated from photographs and physical activity was assessed using questionnaires and accelerometers. RESULTS: Foot shortening strength was greater in HB (4.8 ± 1.9 kg vs 3.5 ± 1.8 kg, P < 0.01). Navicular drop was greater in HB (0.53 ± 0.32 cm vs 0.39 ± 0.19 cm, P < 0.05). Calcaneus stiffness index was greater (right 113.5 ± 17.1 vs 100.5 ± 116.8, P < 0.01 left 109.8 ± 15.7 vs 101.7 ± 18.7, P < 0.05) and Achilles tendon moment arm shorter in HB (right, 3.4 ± 0.4 vs 3.6 ± 0.4 cm, P < 0.05; left, 3.4 ± 0.5 vs 3.7 ± 0.4 cm, P < 0.01). Lower-limb injury prevalence was 8% in HB and 61% in HS. HB subjects spent more time engaged in moderate to vigorous physical activity (60 ± 26 min·d vs 31 ± 13 min·d; P < 0.001). CONCLUSIONS: Significant differences observed in foot parameters, injury prevalence and general foot health between HB and HS suggest that footwear conditions may impact on foot structure and function and general foot health. HB children and adolescents spent more time engaged in moderate to vigorous physical activity and less time sedentary than HS children and adolescents.

Anatomical and histological study to determine the border of sole skin.

PURPOSE: Transfer of a free skin graft from the submalleolar or plantar instep area to the palmoplantar area and finger defects is widely performed; however, the sites and the border of plantar skin have yet to be examined in detail. The aim of this study was to determine the border of sole skin. METHODS: Twelve paraformaldehyde-fixed cadavers were examined. Skin specimens were harvested from an area from the top of the medial malleolus extending to the top of the lateral malleolus of the right foot. The paraffin-embedded skin specimens were analyzed using histological (hematoxylin and eosin, Fontana-Masson, and elastica van Gieson stains) and immunohistochemical (cytokeratin 9) techniques. RESULTS: CK9-positive cells were present at the points between 21 and 78 % of the intermalleolar distance measured from the tops of the medial and lateral malleoli. The melanin index abruptly changed at the points 25 ± 7.1 and 75 ± 4.2 %. The skin thickness and amount of elastic fibers changed greatly at the points between 20 and 30 % and between 70 and 80 % of the intermalleolar distance. CONCLUSIONS: Submalleolar skin is quite different from sole skin. The border of sole skin lies at the points between 20 and 25 % of the intermalleolar distance from the medial malleolus, which macroscopically corresponds to the border of skin maceration. It would be better to use the submalleolar area for grafts for the dorsum of the fingers or toes, and the plantar instep area for the ventral areas of the fingers or toes.

Residual forefoot deformity predicts the need for future surgery in clubfeet treated by Ponseti casting.

Tibialis anterior tendon transfer (TATT) is performed for treatment of recurrent clubfeet. We investigated the predictability of residual adductus on the future need for TATT. A retrospective review of 143 patients with clubfoot was performed. The patients were divided into two groups: group 1 with a history of TATT and group 2 with no TATT. Heel-forefoot angle (HFA) was measured. HFA was compared between the groups. HFA was significantly different between groups 1 and 2. Residual adductus deformity in clubfeet treated by Ponseti casting is a risk factor for future need for surgical treatment.

Simplified versus geometrically accurate models of forefoot anatomy to predict plantar pressures: A finite element study.

Integration of patient-specific biomechanical measurements into the design of therapeutic footwear has been shown to improve clinical outcomes in patients with diabetic foot disease. The addition of numerical simulations intended to optimise intervention design may help to build on these advances, however at present the time and labour required to generate and run personalised models of foot anatomy restrict their routine clinical utility. In this study we developed second-generation personalised simple finite element (FE) models of the forefoot with varying geometric fidelities. Plantar pressure predictions from barefoot, shod, and shod with insole simulations using simplified models were compared to those obtained from CT-based FE models incorporating more detailed representations of bone and tissue geometry. A simplified model including representations of metatarsals based on simple geometric shapes, embedded within a contoured soft tissue block with outer geometry acquired from a 3D surface scan was found to provide pressure predictions closest to the more complex model, with mean differences of 13.3kPa (SD 13.4), 12.52kPa (SD 11.9) and 9.6kPa (SD 9.3) for barefoot, shod, and insole conditions respectively. The simplified model design could be produced in <1h compared to >3h in the case of the more detailed model, and solved on average 24% faster. FE models of the forefoot based on simplified geometric representations of the metatarsal bones and soft tissue surface geometry from 3D surface scans may potentially provide a simulation approach with improved clinical utility, however further validity testing around a range of therapeutic footwear types is required.

Determination of Sex from Footprint Dimensions in a Ghanaian Population.

The present study sought to verify the utility and reliability of footprint dimensions in sex determination in a Ghanaian population. Bilateral footprints were obtained from 126 Ghanaian students (66 males and 60 females) aged 18-30 years at Koforidua Polytechnic using an ink pad and white papers. Seven dimensions-length of each toe (designated T1-T5) from the most anterior point of the toe to the mid-rear heel point, breadth at ball (BAB) and breadth at heel (BAH)--and the heel-ball (HB) index were obtained from each footprint. Some footprint dimensions (i.e. T2, T3, T4 and T5) showed statistically significant bilateral asymmetry in males only. All the footprint dimensions, except HB index, were significantly greater in males than females (p<0.001). Applied singly in discriminant function analysis, the footprint dimensions allowed 69.8%-80.3% of cases to be correctly classified into their sex groups; the accuracy of sex classification was higher using left footprints than right footprints. With all dimensions subjected to stepwise discriminant function analysis 80.3% and 77% of cases could be correctly classified, combining both T5 and BAH for left footprints and T1, BAB and BAH for left footprints respectively. The present study has demonstrated, for the first time among Ghanaian subjects, the utility and reliability of sex determination standards developed from footprint dimensions. The results thus provide the baseline for elaborated studies in the future.

Variability of footprint ridge density and its use in estimation of sex in forensic examinations.

The present study deals with a comparatively new biometric parameter of footprints called footprint ridge density. The study attempts to evaluate sex-dependent variations in ridge density in different areas of the footprint and its usefulness in discriminating sex in the young adult population of north India. The sample for the study consisted of 160 young adults (121 females) from north India. The left and right footprints were taken from each subject according to the standard procedures. The footprints were analysed using a 5 mm × 5 mm square and the ridge density was calculated in four different well-defined areas of the footprints. These were: F1 - the great toe on its proximal and medial side; F2 - the medial ball of the footprint, below the triradius (the triradius is a Y-shaped group of ridges on finger balls, palms and soles which forms the basis of ridge counting in identification); F3 - the lateral ball of the footprint, towards the most lateral part; and F4 - the heel in its central part where the maximum breadth at heel is cut by a perpendicular line drawn from the most posterior point on heel. This value represents the number of ridges in a 25 mm(2) area and reflects the ridge density value. Ridge densities analysed on different areas of footprints were compared with each other using the Friedman test for related samples. The total footprint ridge density was calculated as the sum of the ridge density in the four areas of footprints included in the study (F1 + F2 + F3 + F4). The results show that the mean footprint ridge density was higher in females than males in all the designated areas of the footprints. The sex differences in footprint ridge density were observed to be statistically significant in the analysed areas of the footprint, except for the heel region of the left footprint. The total footprint ridge density was also observed to be significantly higher among females than males. A statistically significant correlation is shown in the ridge densities among most areas of both left and right sides. Based on receiver operating characteristic (ROC) curve analysis, the sexing potential of footprint ridge density was observed to be considerably higher on the right side. The sexing potential for the four areas ranged between 69.2% and 85.3% on the right side, and between 59.2% and 69.6% on the left side. ROC analysis of the total footprint ridge density shows that the sexing potential of the right and left footprint was 91.5% and 77.7% respectively. The study concludes that footprint ridge density can be utilised in the determination of sex as a supportive parameter. The findings of the study should be utilised only on the north Indian population and may not be internationally generalisable.