Pronation Angle Research Articles

Runners With Anterior Knee Pain Use a Greater Percentage of Their Available Pronation Range of Motion

"Excessive" pronation is often implicated as a risk factor for anterior knee pain (AKP). The amount deemed excessive is typically calculated using the means and standard deviations reported in the literature. However, when using this method, few studies find an association between pronation and AKP. An alternative method of defining excessive pronation is to use the joints' available range of motion (ROM). The purposes of this study were to (1) evaluate pronation in the context of the joints' ROM and (2) compare this method to traditional pronation variables in healthy and injured runners. Thirty-six runners (19 healthy, 17 AKP) had their passive pronation ROM measured using a custom-built device and a motion capture system. Dynamic pronation angles during running were captured and compared with the available ROM. In addition, traditional pronation variables were evaluated. No significant differences in traditional pronation variables were noted between healthy and injured runners. In contrast, injured runners used significantly more of their available ROM, maintaining a 4.21° eversion buffer, whereas healthy runners maintained a 7.25° buffer (P = .03, ES = 0.77). Defining excessive pronation in the context of the joints' available ROM may be a better method of defining excessive pronation and distinguishing those at risk for injury.

Sequelae of surgical options in the older brachial plexus birth palsy pronation deformity

Objective To evaluate the radial rotation osteotomy and ulnadouble rotation osteotomy obstetric brachial plexus injury (obstetric brachial plexus palsy) forearm pronation deformity sequelae value.Methods From August 2007 to August 2011, twenty cases of obstetric brachial plexus palsy sequelae in children with forearm pronation deformity, the implementation of a simple radial rotating radial osteotomy (5cases),double-rotation radius and ulna osteotomy (15 cases) and two surgical type,and by 6 to 54 months after surgery (mean 25 months) follow-up.The groupfunctions to forearm pronation angle and conscious function improvement as the evaluation criteria. Results The 15 cases of radius and ulna osteotomy in children with dual function and appearance in 14 cases significandy improved,one case of supination deformity;five underwent simple radial pronation osteotomy,three patients had improved function and appearance,followed up for 6 months, eight months after the merger which radial head dislocation in 2 cases due to poor efficacy of dual-line radius and ulna osteotomy, twenty patients in this group did not appear nonunion.Conclusion Simple radial rotation osteotomy surgery in obstetric brachial plexus palsy forearm pronation deformity complications without radial head dislocation has some value, radius and ulna double osteotomy in forearm pronation deformity with radial head dislocation aftermath of the effect is more excellent. Key words: Branchial plexus birth palsy; Birth trauma; Radius; Ulna; Rotation osteotomy; Radial head dislocation

노인 건강증진용 신발의 운동과학적 효과분석

본 연구에서는 국내외 실버화와 일반적인 운동화에 대한 1차 운동기능학적 분석을 통하여 노인에게 가장 적합한 신발을 정하고 2차 운동생리학적 실험을 통해 체지방률변화, 운동강도에 따른 대사량의 변화 그리고 에너지 소비량의 변화를 분석하였다. 본 연구의 대상으로는 특별한 질병을 가지고 있지 않은 남자 어른들 20명을 대상으로 하였으며, 평균나이는 <TEX>$62.78{\pm}4.32$</TEX>세, 신장은 <TEX>$170.89{\pm}3.56cm$</TEX> 그리고 몸무게는 <TEX>$75.12{\pm}8.76kg$</TEX>이었다. 실험 전 실험에 대한 충분한 설명을 하고 동의서를 받은 후 데이터를 수집하였다. 본 연구를 위하여 운동 기능학적 실험과 운동 생리학적 실험을 수행하였으며, 본 연구결과 걷기나 달리기 시 최초 발 뒤꿈치 접촉 시 발이 회내(pronation)되는 정도와 최대 회내가 되는 정도를 알아 본 결과 걷기속도가 가장 빠르게 나온 B형의 신발이 회내값(<TEX>$-2.3{\pm}1.05^{\circ}$</TEX>)이 가장 크게 나타났으며 일반걷기용 신발에서 가장 작은 값(<TEX>$-1.5{\pm}0.49^{\circ}$</TEX>)을 보여주고 있다. 또한 노인들의 일상생활에서 착용하는 건강증진용 신발을 대상으로 운동 생리학적 부분을 살펴보면 체지방율의 변화는 모든 그룹에서 감소는 하였으나, 통계적으로 유의한 차이가 나타나지 않았는데, 이는 체지방율의 변화를 가져오기 위해서 일시적인 운동이 아닌 규칙적이고 장기적인 운동이 필요할 것으로 사료되어지며, 노인들이 건강증진용 기능화를 장기적으로 착용하여 운동할 경우 체 지방율에 긍정적인 영향을 미칠 것으로 사료되어진다. The purpose of this study was to analyze and compare the effects of exercise science of shoes for Aged' health promotion. Kinematic and kinetic data were collected using cinematography and the Zebris system (Zebris Emed Sensor Platform, GR-DVL9800) to analyze pressure of foot and ground reaction force. Subjects recruited were 20 healthy elderly men. They walked at 1.36m/sec velocity wearing type A (domestic), type B (foreign) and walking shoes (A company). One-way ANOVA was used to analyze statistics. The results were as following: no significant differences were observed in gait variables among the three groups (p<0.05). There was a significant difference in max pronation angle of heels examined among the three groups (p<0.05). There were no significant differences in kinetic variables (ground reaction force and max pressure) among the three groups (p<0.05). A physiology study was performed to analyze the effects of walking with shoes with silver added to them on percent body fat, resting metabolic rate and energy expenditure. Sixty adults males were recruited from the public health center. They were divided into four groups. C: control group (n=20), EY: elderly Y group (n=20), and EO: elderly O group (n=20). The results of this study were as follows: percent body fat was decreased following each exercise period, however, not all the groups showed a significant difference. The change of resting metabolic rate was significantly increased in HI (high intensity) and LI (low intensity) periods in the C and EY groups. However, there was no significant difference in the EO group. The mean energy expenditure during and after exercise were significantly lowered in all periods compared to the control group.

Application of de-rotation osteotomy in the treatment of obstetric brachial plexus palsy (OBPP)

Objective To evaluate the value of de-rotation ostectomy of ulna and radius in the treatment of sequelae of obstetric brachial plexus palsy (OBPP). Methods From August 2007 to October 2009, a total of 13 cases of OBPP with elbow sequelae forearm pronation contracture and radial head dislocation were treated with de-rotation ostectomy of the ulna and radius. Postoperative forearm function was evaluated by improvement in pronation angle. Results Postoperative follow-up period ranged from 6 to 16 months, with an average of 8 months. Forearm was positioned at 30° of pronation. Both function and appearance of the forearm were improved.Conclusion De-rotation ostectomy of ulna and radius is an effective treatment for elbow sequelae of OBPP. Key words: Brachial plexus; Paralysis,obstetric; Forearm; De-rotation osteotomy

Relation Between Lower Limb Alignment And Injury In Runners With Achilles Tendinopathy

Although there is limited support from the literature, static lower limb alignment has been proposed as an intrinsic risk factor to running injuries. However, most of the studies have investigated a group of injuries and there is limited evidence on specific injuries. PURPOSE: The aim of this study was to examine the relation between lower limb static measurements and Achilles Tendinopathy injury. METHODS: Thirty four injury free runners (CON) (19 males:15 females; weight: 67.8±10.5 kg; height: 1.71±0.09 m; age: 37.0±9.2 years) and twenty one runners with Achilles tendinopathy (AT) (18 males:7 females; weight: 77.6±12.6 kg; height: 1.78±0.07 m; age: 41.8± 9.7 years) were selected for this study. The following lower limb static measurements were performed on both legs: rearfoot alignment, pronation angle at 45 degrees, Q angle, standing foot angle, navicular drop, forefoot alignment, subtalar joint passive range of motion for eversion and inversion, knee range of motion, functional foot type, knee alignment and leg length. The data of the left and right side were compared between groups and the afflicted side was compared to a random side of the uninjured group, matched with the percentage of left and right foot equal to the injured group. The relationship between lower limb alignment and the incidence of injury was evaluated by calculating 95% confidence interval (95% CI) for the difference between the mean measures in the injured and non-injured runners. RESULTS: None of the anthropometrical variables of the right leg and injured limb versus the matched limb from uninjured group were considered significant discriminator between injured and uninjured runners. However, on the left side subtalar joint passive range of motion for eversion (STJE) and knee range of motion (KROM) were considered significant discriminators between the two groups (CON: 8.73±5.51; AT: 6.00±3.65, 95% CI -0.49 to 0.00; CON: 140.1±8.1; AT: 135.6±5.8, 95% CI -0.51 to -0.04). CONCLUSIONS: Although subtalar joint passive range of motion for eversion and knee range of motion were significantly lower in runners with Achilles injury, this result was not replicated for the right leg and on the injured versus matched leg. We can therefore conclude that static lower limb alignment is not associated with Achilles Tendinopathy.

Treatment of Hallux Valgus with Three-dimensional Modification of Mitchell’s Osteotomy

Mitchell's osteotomy gives very good results but there are still some cases where the original method, as well as its modification, cannot address all aspects of deformity. We modified the original Mitchell's method to address pronation and plantar displacement of the first metatarsal. Modification includes formation of lateral and plantar spur with metatarsal displacement and derotation of distal metatarsal fragment in the frontal and horizontal planes with stable screw fixation. We present midterm results of the first 60 patients compared to the original Mitchell method (30 patients). Differences between the groups postoperatively were in declination angle, postoperative metatarsalgia rate, and first metatarsal pronation angle. The technique described eliminated many of the disadvantages of Mitchell's method.

The Role of Foot Pronation in the Development of Femoral and Tibial Stress Fractures: A Prospective Biomechanical Study

To examine whether dynamic parameters of foot pronation are risk factors for the development of stress fractures of the femur and tibia. Observational prospective study. Infantry basic training course. 473 recruits evaluated for stress fractures of the femur and tibia every 2 weeks during 14 weeks of infantry basic training. The final analysis included 405 recruits. Two weeks before commencement of training, the recruits were evaluated during treadmill walking for their subtalar joint kinematics. Five independent variables were measured bilaterally: maximal pronation angle during the stance, pronation range of motion, time from heel strike to maximum pronation, pronation mean angular velocity, and time to maximum pronation as a percent of the total stance time. Stress fractures of the femur and tibia. These were considered positive only when proven by imaging. Ten percent of the participants were diagnosed with stress fractures of the femur and tibia. Recruits with longer duration of foot pronation had reduced odds ratio to develop this injury. Longer duration of foot pronation may have a protective effect from stress fractures of the femur and tibia. This finding may promote the understanding of stress fracture pathomechanism, assist in the identification of subjects with increased risk who need augmented monitoring throughout training, and assist in future planning of impact reducing aids.

A protocol for clinical evaluation of the carrying angle of the elbow by anatomic landmarks

The aim of this work was to present an in vivo protocol to estimate the carrying angle of the elbow in full extension. Forty-four arms were measured by using an electrogoniometer to acquire 3-dimensional coordinates of the landmarks. An algorithm based on the Cardan decomposition method was used to compute the carrying angle and the flexion and pronation angles of the elbow. The mean carrying angle was 12.42 degrees +/- 4.06 degrees , in agreement with the literature and with values obtained by a standard goniometer (r = 0.46; P = .000). Our protocol provided excellent repeatability (interclass correlation coefficient [ICC] = 0.85), greater than a goniometer (ICC = 0.76), and a standard error of measurement of only 1.62 degrees . Flexion was a significant factor (P = .01) in carrying angle estimation. This study suggests that the carrying angle cannot be estimated independently by the flexion angle, even when measured in apparently full extension, and it could be useful in elbow disorders, such as fractures or epicondylar disease management and evaluation of elbow reconstruction.

The Association between Computer Typing Style and Typing Speeds

Typing styles vary among keyboard users; however few studies have investigated the association between typing style and typing speed. The purpose of this paper is to describe the differences in typing speed between typists who rarely assume extreme postures of the wrist, hands, and fingers with typists who often assume extreme postures. The paper also examines the association between other typing behaviors, such as using a wrist support, and typing speed. Forty computer users were videotaped while typing a standardized text. Their typing postures were rated using the Keyboard Personal Computer Style instrument (K-PeCS). One-way ANOVA's were used to compare typing speed between the rating levels of several items on the K-PeCS. Results suggest that those who frequently isolate their 5th digit are significantly faster than those who always isolate their 5th digit. Subjects who “float” their wrists, translate their wrist/hands, do not change pro-nation angles, use moderate to high force, and use more digits appear to type faster than those who do not.

Effects of three keyboard designs on wrist and forearm postures and typing task performance

The main objective of this study was to investigate postures of both wrists and the right forearm, associated with use of three different computer keyboards. The investigated keyboards were (1) a traditional keyboard, (2) the Microsoft® natural keyboard, and (3) an experimental keyboard. Typing with the experimental keyboard appears to improve left wrist and right forearm postures by reducing left wrist extension angles and right forearm pronation angles, However, non-sagittal plane left wrist posture, as well as sagittal and non-sagittal right wrist posture did not appear to be affected. It was also noted that left wrist postures were in low or moderate injury risk zones for substantially greater percentages of the trial durations with the experimental keyboard, than with either of the other keyboards. Typing speed and accuracy were reduced with the experimental keyboard; however, it was suspected that lack of familiarity with the experimental keyboard was associated with the poorer performance.

유산소 운동능력 향상을 위한 중량물 부가 신발의 기능성 평가

The purpose of this study was to evaluate the function and the safety of an additional weight shoe developed for the improvement of aerobic capacity, and to improve some problems found by subject's test for an additional weight shoe. The subjects employed for this study were 10 college students. 4 video cameras, AMTI force platform and Pedar insole pressure distribution measurement device were used to analyze foot motions. The results of the study were as follows: 1 The initial achilles tendon angle and initial rearfoot pronation angle of an additional weight shoe during walking were 183.7 deg and 2.33 deg, respectively, and smaller than a barefoot condition. Maximum achilles tendon angle and the angular displacement of achilles tendon angle were 185.35 deg and 4.21 deg respectively, and smaller than barefoot condition. Thus rearfoot stability variables were within the permission value for safety. 2. Maximal anterior posterior ground reaction force of additional weight shoe was appeared to be 1.01-1.2 B.W., and was bigger than a barefoot condition. The time to MAPGRF of an additional weight shoe was longer than a barefoot condition. Maximal vertical ground reaction force of additional weight shoe was appeared to be 2.3-2.7 B.W., and was bigger than a barefoot condition in propulsive force region. But A barefoot condition was bigger in braking force region. The time to MVGRF of an additional weight shoe was longer than a barefoot condition. 3. Regional peak pressure was bigger in medial region than in lateral region in contrast to conventional running shoes. The instant of regional peak pressure was M1-M2-M7-M4-M6-M5 -M3, and differed form conventional running shoes. Regional Impulse was shown to be abnormal patterns. There were no evidences that an additional weight shoe would have function and safety problems through the analysis of rearfoot control and ground reaction force during walking. However, There appeared to have small problem in pressure distribution. It was considered that it would be possible to redesign the inner geometry. This study could not find out safety on human body and exercise effects because of short term research period. Therefore long term study on subject's test would be necessary in the future study.

Effect of gender and defensive opponent on the biomechanics of sidestep cutting.

Anterior cruciate ligament (ACL) injuries often occur in women during cutting maneuvers to evade a defensive player. Gender differences in knee kinematics have been observed, but it is not known to what extent these are linked to abnormal neuromuscular control elsewhere in the kinetic chain. Responses to defense players, which may be gender-dependent, have not been included in previous studies. This study determined the effects of gender and defense player on entire lower extremity biomechanics during sidestepping. Eight male and eight female subjects performed sidestep cuts with and without a static defensive opponent while 3D motion and ground reaction force data were recorded. Peak values of eight selected motion and force variables were, as well as their between-trial variabilities, submitted to a two-way (defense x gender) ANOVA. A Bonferroni-corrected alpha level of 0.003 denoted statistical significance. Females had less hip and knee flexion, hip and knee internal rotation, and hip abduction. Females had higher knee valgus and foot pronation angles, and increased variability in knee valgus and internal rotation. Increased medial ground reaction forces and flexion and abduction in the hip and knee occurred with the defensive player for both genders. A simulated defense player causes increased lower limb movements and forces, and should be a useful addition to laboratory protocols for sidestepping. Gender differences in the joint kinematics suggest that increased knee valgus may contribute to ACL injury risk in women, and that the hip and ankle may play an important role in controlling knee valgus during sidestepping. Consideration of the entire lower extremity contributes to an understanding of injury mechanisms and may lead to better training programs for injury prevention.

The “clenched pencil” view: A modified clenched fist scapholunate stress view

Traditional radiographic imaging of the scapholunate interval is complicated by the lack of a view that combines the dynamism of the clenched-fist stress view with the ability to reliably duplicate the precise angle of pronation that shows optimally the scapholunate interval. We describe a simple radiographic technique that combines these 2 criteria that we have found helpful in the office diagnosis of scapholunate dissociation. (J Hand Surg 2003;28A:414-418. Copyright © 2003 by the American Society for Surgery of the Hand.)

Mathematical model of the evolution of locomotion in tetrapods.

During the locomotion of Monotremata and lower tetrapods, their limbs are spread apart, so that the stylopodias (femur and shoulder) move in an almost horizontal plane. Retraction of the stylopodias in the phase of support is observed in all species of these tetrapods [1–4, 6, 7, 9]. Only representatives of the family Tachyglossidae of the order Monotremata are characterized by an absence of limb retraction [5, 8]. Therefore, we divided the locomotion patterns into two groups: retraction (the shoulder moves backward about the vertical axis) and pronation (the shoulder turns around the horizontal axis). These groups were given their names based on the main locomotor movement of the shoulder during the stage of support. The main features of morphological and kinematic difference between these locomotion patterns are summarized in Table 1. The locomotion efficiency depends on minimization of energy expenditures for increasing the step length and for preventing the animal body from falling down. However, the characteristic features of the locomotor apparatus in evolutionary ancestors of modern animals may also have a significant effect on the locomotion pattern in the latter. For example, the shoulder bone of primitive tetrapods was very short. Therefore, both shoulder retraction and shoulder joint protraction were equally suitable for locomotion of these animals. It was also reported [4–6, 8] that, in animals adapted to the two locomotion patterns, the angle of the shoulder joint pronation in the support stage was about 60 ° . To perform pronation in the support stage, the shoulder joint at the stage of transfer should supinate. The main shoulder joint supinators in Monotremata are m. supraspinatus and m. infraspinatus. The two muscles prevent the stylopodias from being retracted or protracted. The other tetrapods are devoid of such mechanism. Let us construct a model intended to determine which structural and kinematic features of the locomotor apparatus determine the step length. For the sake of simplicity, let the stylopodia move in a horizontal plane and step kinematics be symmetrical about the middle point of the phase of support. In this case, the step length (body displacement relative to the point of support) is uniquely determined by the following factors: the stylopodia and zeigopodia lengths, size of body bends (undulation), retraction of the stylopodia, shoulder joint pronation, flexion and extension, as well as adduction and abduction in the elbow joint. In the case of extension, it is suggested that, if the palm is under the elbow joint or abducted outwards or inwards, it

Kinematics of flap-bounding flight in the zebra finch over a wide range of speeds

ABSTRACTIt has been proposed elsewhere that flap-bounding, an intermittent flight style consisting of flapping phases interspersed with flexed-wing bounds, should offer no savings in average mechanical power relative to continuous flapping unless a bird flies 1.2 times faster than its maximum range speed (Vmr). Why do some species use intermittent bounds at speeds slower than 1.2Vmr The ‘fixed-gear hypothesis’ suggests that flap-bounding is used to vary mean power output in small birds that are otherwise constrained by muscle physiology and wing anatomy to use a fixed muscle shortening velocity and pattern of wing motion at all flight speeds; the ‘body-lift hypothesis’ suggests that some weight support during bounds could make flap-bounding flight aerodynamically advantageous in comparison with continuous flapping over most forward flight speeds. To test these predictions, we studied high-speed film recordings (300 Hz) of wing and body motion in zebra finches (Taenopygia guttata, mean mass 13.2 g, N=4) taken as the birds flew in a variable-speed wind tunnel (0–14 m s−1). The zebra finches used flap-bounding flight at all speeds, so their flight style was unique compared with that of birds that facultatively shift from continuous flapping or flap-gliding at slow speeds to flap-bounding at fast speeds. There was a significant effect of flight speed on all measured aspects of wing motion except percentage of the wingbeat spent in downstroke. Changes in angular velocity of the wing indicated that contractile velocity in the pectoralis muscle changed with flight speed, which is not consistent with the fixed-gear hypothesis. Although variation in stroke-plane angle relative to the body, pronation angle of the wing and wing span at mid-upstroke showed that the zebra finch changed within-wingbeat geometries according to speed, a vortex-ring gait with a feathered upstroke appeared to be the only gait used during flapping. In contrast, two small species that use continuous flapping during slow flight (0–4 m s−1) either change wingbeat gait according to flight speed or exhibit more variation in stroke-plane and pronation angles relative to the body. Differences in kinematics among species appear to be related to wing design (aspect ratio, skeletal proportions) rather than to pectoralis muscle fiber composition, indicating that the fixed-gear hypothesis should perhaps be modified to exclude muscle physiology and to emphasize constraints due to wing anatomy. Body lift was produced during bounds at speeds from 4 to 14m s−1. Maximum body lift was 0.0206 N (15.9 % of body weight) at 10 m s−1; body lift:drag ratio declined with increasing air speed. The aerodynamic function of bounds differed with increasing speed from an emphasis on lift production (4–10 m s−1) to an emphasis on drag reduction with a slight loss in lift (12 and 14 m s−1). From a mathematical model of aerodynamic costs, it appeared that flap-bounding offered the zebra finch an aerodynamic advantage relative to continuous flapping at moderate and fast flight speeds (6–14 m s−1), with body lift augmenting any savings offered solely by flap-bounding at speeds faster than 7.1 m s−1. The percentage of time spent flapping during an intermittent flight cycle decreased with increasing speed, so the mechanical cost of transport was likely to be lowest at faster flight speeds (10–14 m s−1).

Functional properties of graphic workspace: assessment by means of a 3D geometric arm model

Computer simulations aimed at assessing functional characteristics of the graphic workspace are presented. The simulations involve a 10-df kinematic model of the distal part of the writing arm, and yield the effective workspace of the pen tip under two types of kinematic constraints. The first constraint involves fixing the forearm under various pronation angles, the second governs the protrusion of the pen tip from the finger tips. The effective workspace is analyzed in terms of the effort required to reach the various locations in it, where effort is defined in terms of the joint angles adopted by the wrist and fingers to reach each location. The simulation results show agreements between the distribution of required effort over the workspace and known stroke-direction preferences in drawing. Furthermore, they predict shifts in the biases that are thought to lead to these preferences as a function of both hand pronation and pen protrusion.

Pronation angle of the rear foot during running in relation to load

In 20 volunteers the relationship between rear-foot pronation and increasing physical exertion during treadmill ergometry was examined. In order to assess the influence of regularly performed running training a group of 10 endurance trained middle- and long-distance runners (age: 27.4 +/- 4.9 years; weight: 71.0 +/- 8.8 kg; height: 184.2 +/- 8.3 cm) was compared to another group of 10 untrained subjects (age: 24.7 +/- 2.1 years; weight: 73.3 +/- 9.8 kg; height: 179.1 +/- 8.3 cm). The examinations were carried out on a treadmill using a high-frequency motion analyzing system. Heart rate, blood lactate as well as rear-foot pronation were measured. Regarding heart rate and lactate concentration there were significant differences between trained and untrained volunteers. The pronation angle increased with higher speed up to a maximum of 6.54 +/- 4.22 degree for the trained group and 6.84 +/- 4.59 degree for the untrained group. With reference to maximal as well as submaximal stages the pronation angles showed no significant differences between both groups. Following the maximal exercise level the runners performed an additional 3 min run with a velocity reduced by 8 km/h compared to the maximal speed. At this level the total group as well as the untrained group showed significantly greater pronation angles compared to those of the corresponding velocity at the beginning of the test. The extent of the differences, however, was not significantly correlated with the lactate levels. Our results demonstrate that the increase of the pronation angle is a function of the running speed. But there is also an influence of fatigue, which depends neither on the running velocity nor on the lactate levels during exercise. Therefore, further investigations should emphasize the question which factors are responsible for this effect.

Anatomic Determinants of First Metatarsophalangeal Flexion Moments in Hallux Valgus

A laboratory cadaver model was used to assess the effects of the major anatomic components of hallux valgus deformity on first metatarsophalangeal flexion moments. The individual components of the flexor hallucis longus' effective tendon moment arm were evaluated as a function of imposed hallux valgus, of hallux pronation, and of combined hallux valgus and pronation. To simulate the effects of distal first metatarsal surgery, the components' changes after metatarsal head lateral translation or supination were assessed. Significant changes in effective tendon moment arm occurred with increases in the hallux valgus angle, with changes in the hallux pronation angle, and with combined increases in the hallux valgus angle and hallux pronation angles. The changes involved primarily were a redirection of the moment vector's projection within the superior and inferior plane or medial and lateral plane, rather than an appreciable alteration of the magnitude of the resultant. By contrast, neither translational nor rotational displacements of the metatarsal head influenced any of the individual components of the effective tendon moment arm.

Positioning aid solves the reproducibility problem during oblique hand radiography: a cheap and effective solution.

A commercially available positioning device was evaluated to assess whether standardized positioning of hand radiographs for the pronated oblique view was facilitated. One hundred hands of volunteers were radiographed in postero-anterior, anteroposterior and pronated oblique projections, with and without use of the positioning device, and with and without application of a plaster cast. The variation in pronation angle in the uncovered hand was 6 degrees with, and 24 degrees without the positioning device. Use of the device diminished intra- and inter-positioning variation by 14 degrees and 18 degrees respectively. A plaster cast led to a variation of up to 26 degrees, despite use of the device. Use of the positioning device improved consistency for the pronated oblique radiograph. There was no improvement with a cast on the forearm.

High Heeled Shoes: Their Effect on Center of Mass Position, Posture, Three-Dimensional Kinematics, Rearfoot Motion, and Ground Reaction Forces

This study investigated changes in center of mass position, forefoot loading, lumbar curvature, and pelvic tilt during standing and ground reaction forces, rearfoot motion, sagittal lower extremity kinematics, and shoulder and pelvic rotations of women walking at 1.4 m.s-1 in different heights of high heeled shoes. Three different heel heights (1.91, 3.81, 7.62cm) were worn by each of 11 women. Vertical forces applied to the forefoot during standing increased with increased heel height. No significant differences in average lumbar curvature or pelvic tilt among shoe heights were found. Significant increases in vertical and anteroposterior forces during walking were found with increased heel height, and foot abduction angle during support showed significant less abduction with higher heels. With an increase in heel height the minimum vertical force (at midstance) and the maximum vertical force during the second half of support both occurred later in the support phase, whereas the maximum and minimum anteroposterior forces occurred earlier in support. Rearfoot angle measures obtained from high-speed video analysis showed a significantly greater angle of supination at footstrike and a smaller angle of maximum pronation in the high compared with the low heeled shoes. Ankle angles throughout the gait cycle showed a significant increase in plantarflexion with increased heel height. Maximum knee angle during swing and knee extension velocity decreased with increased heel height. Other sagittal plane kinematic measures and measures to hip and shoulder rotation derived from three-dimensional (3-D) cine data showed few consistent effects of heel height.(ABSTRACT TRUNCATED AT 250 WORDS)