Difference In Maximum Force Research Articles

A quantitative study of mechanics in the treatment of atlantoaxial joint disorder by tendon relaxation manipulation

To explore dose-effect relationship of biomechanical parameters in treating atlantoaxial joint disorder by slimming manipulation. From October 2022 to May 2023, 18 patients with atlantoaxial joint disorders were treated, including 10 males and 8 females;aged from 24 to 27 years old with an average of (25.50±1.10) years old;CT of cervical vertebra showed 16 patients with right side distortion and 2 patients with left side distortion. The mechanical parameters of treatment of atlantoaxial joint disorder by tendon relaxation manipulation were measured by wearing massage manipulation gloves. The magnitude, frequency and mechanical curve of force during tendon relaxation and starting force, pulling force, pulling time and mechanical curve during rehabilitation were quantified, the differences between the affected and contralateral manipulations were compared. The maximum force and frequency of Fengchi(GB20) on the affected side were (19.82±2.02) N and (116.83±14.49) times/min, and opposite side were (13.87±2.19) N and (188.89±16.03) times/min, respectively. There were statistically difference in the maximum force and frequency of both sides (P<0.05). The maximum force and frequency of Quepen (ST12) on the affected side were (14.44±3.27) N and (139.06±28.47) times/min, and those on the opposite side were (9.41±1.38) N and (142.50±28.47) times/min. There was difference in maximum force on both sides (P<0.05). The starting force, turning force and turning time of the affected side were (14.16±5.98) N, (11.56±6.63) N, (0.14±0.03) S, and the contralateral side were (8.94±3.39) N, (8.30±4.64) N, (0.18±0.04) S, respectively. The difference of starting force, turning force and turning time on both sides were statistically significant (P<0.05). By applying a light relaxation force on the affected side, the mechanical balance between cervical vertebrae could be restored, and recovery trend of atlantoaxial joint disorder could be strengthened. On this basis, the atlantoaxial odontoid process could be reversed by applying a light rotation force, which reflects the characteristics of high safety of the manipulation.

Self-assessment of strength abilities in climbing: Impact of skill level

Introduction&#x0D; Many climbers believe that they are stronger in crimp finger position than in open hand position. However, compared to open hand, crimped fingers are associated with higher pulley forces increasing the risk of injuries. Climbing expertise may influence the estimation of strength, i.e., the better the climber, the better the self-assessment. This study therefore aimed to find out whether climbing expertise influences self-assessment of finger flexor strength in half-crimp and in open hand position.&#x0D; Methods&#x0D; Data was collected at the Hands-On Science Booth of the Climbing World Championships in Bern. Participants had to fill out a questionnaire including a self-assessment of their climbing expertise and of their maximum finger strength for both hands as well as both finger positions. Afterwards, maximum finger strength was measured on an instrumented campus board: Participants placed the to-be-measured hand on a self-selected rung (depth of 23 mm) and then tried to transfer as much force as possible from their feet to their fingers.&#x0D; Results&#x0D; The analysis was based on 38 intermediate and 36 advanced climbers. Due to the limited number of participants in the lower grade (n = 0) and elite (n = 2) level, those skill levels were not considered. Advanced climbers generated significantly greater forces than intermediate climbers across all four measured conditions (t-tests, all p &lt; 0.01). For both groups, neither in the dominant nor in the non-dominant hand a significant difference in maximum force was observed, e.g., dominant hand, intermediates: or advanced climbers: . Intermediate climbers did neither over- nor underestimate their strength in half-crimp position compared to open hand (paired t-test, p = 0.91 for dominant, p = 0.077 for non-dominant hand). In contrast to the dominant hand, advanced climbers significantly overestimated their strength in half-crimp position for the non-dominant hand (on average 9%, Cohen’s d 0.64, p &lt; 0.01).&#x0D; Discussion/Conclusion&#x0D; Our results confirm the positive correlation between finger strength and climbing level. We also confirm that on a 23 mm rung, greater forces can be generated with in open hand compared to half-crimp (Winkler et al., 2023). With larger hold depths, force generated in open hand significantly increases (Amca et al., 2012), while for smaller holds, force exerted in half-crimp position exceeds that of open hand (Winkler et al., 2023). Hence, at least for larger holds, we recommend adopting an open hand position as preventive measure against finger injuries. Advanced climbers may tend to inaccurately self-assess their strength due to their greater engagement with peers, potentially leading to the circulation of misinformation. Note that participants were instructed to provide a general self-assessment of their strength rather than for a 23 mm deep rung, i.e., they may have had a smaller hold in mind.&#x0D; References&#x0D; Amca, A. M., Vigouroux, L., Aritan, S., &amp; Berton, E. (2012). Effect of hold depth and grip technique on maximal finger forces in rock climbing. Journal of Sports Sciences, 30(7), 669-677. https://doi.org/10.1080/02640414.2012.658845&#x0D; Winkler, M., Künzell, S., &amp; Auguste, C. (2023). Competitive performance predictors in speed climbing, bouldering, and lead climbing. Journal of Sport Sciences, 41(8), 736-746. https://doi.org/10.1080/02640414.2023.2239598

Elastic property and fracture mechanics of lateral branch-branch junctions in cacti: A case study of Opuntia ficus-indica and Cylindropuntia bigelovii.

Species with various reproductive modes accompanied by different mechanical properties of their (lateral) branch-branch junctions have evolved in the cactus subfamily Opuntioideae. Older branches of Opuntia ficus-indica with fracture-resistant junctions often bear flowers and fruits for sexual reproduction, whereas younger branches break off easily and provide offshoots for vegetative propagation. Cylindropuntia bigelovii plants are known for their vegetative reproduction via easily detachable branches that can establish themselves as offshoots. We characterized the elastic and fracture behaviors of these lateral junctions by tensile testing and analyzed local strains during loading. Additionally, we carried out finite element analyses to quantify the influence of five relevant tissue layers on joint elastic behavior. Our fracture analysis revealed various fracture modes: (i) most young samples of Opuntia ficus-indica failed directly at the junction and had smooth fracture surfaces, and relative fracture strain was on median 4% of the total strain; (ii) most older samples of Opuntia ficus-indica failed at the adjacent branch and exhibited rough fracture surfaces, and relative fracture strain was on median 47%; (iii) most samples of Cylindropuntia bigelovii abscised directly at the junction and exhibited cup and cone surfaces, and relative fracture strain was on median 28%. Various geometric and mechanical properties such as junction area, fracture energy, and tensile strength were analyzed with respect to significant differences between species and age of sample. Interestingly, the abscission of lateral branches naturally triggered by wind, passing animals, or vibration showed the following differences in maximum force: 153 N (older Opuntia ficus-indica), 51 N (young Opuntia ficus-indica), and 14 N (Cylindropuntia bigelovii).

Fracture Fixation Strength in Metacarpal Plating Versus Intramedullary Nailing Using a 3-Point Bending Model: A Cadaveric, Biomechanical Study

The purpose of our study was to evaluate the ultimate load to failure for 2 metacarpal fracture fixation strategies, plating versus intramedullary nailing, and then compare them to the native metacarpal. Our hypothesis was that the intramedullary nail after fracture fixation would more closely restore the native strength of the metacarpal when compared to plate fixation. Matched pairs of cadaveric hands (age range, 19-49; 5 men and 6 women) were dissected to produce 88 intact and equally distributed metacarpals (little, ring, middle, and index fingers). The metacarpals were then randomly selected to undergo either plate fixation or intramedullary nail fixation. A 3-point bending model was used to test the native metacarpal strength to the point of fracture and, subsequently, the fracture fixation construct. The data were then compared against the native metacarpal for normalized load to failure, normalized displacement, and stiffness. The normalized maximum force (ratio of fixation:native) for the intramedullary nail specimens was significantly closer to normal than for the plated specimens for the little, middle, and index fingers, as well as for all metacarpals combined. We did not detect a difference in maximum force for the ring finger. When compared to plate fixation, metacarpal intramedullary nailing more closely restores the ultimate load to failure of the native metacarpal after midshaft fracture. For metacarpal fracture patterns amenable to intramedullary screw fixation, an intramedullary nail has biomechanical properties that are superior to a plate and screws in a 3-point bending model.

Morphology, performance and fluid dynamics of the crayfish escape response.

Sexual selection can result in an exaggerated morphology that constrains locomotor performance. We studied the relationship between morphology and the tail-flip escape response in male and female rusty crayfish (Faxonius rusticus), a species in which males have enlarged claws (chelae). We found that females had wider abdomens and longer uropods (terminal appendage of the tail fan) than males, while males possessed deeper abdomens and larger chelae, relative to total length. Chelae size was negatively associated with escape velocity, whereas longer abdomens and uropods were positively associated with escape velocity. We found no sex-specific differences in maximum force generated during the tail flip, but uropod length was strongly, positively correlated with tail-flip force in males. Particle image velocimetry (PIV) revealed that the formation of a vortex, rather than the expulsion of fluid between two closing body surfaces, generates propulsion in rusty crayfish. PIV also revealed that the pleopods (ventral abdominal appendages) contribute to the momentum generated by the tail. To our knowledge, this is the first confirmation of vortex formation in a decapod crustacean.

Handheld laparoscopic robotized instrument: progress or challenge?

Handheld laparoscopic robotized instruments have been developed to combine the advantages of a robotic operation system and conventional laparoscopic instruments. Direct objective standards are needed to quantify surgeons' skill level and validate the advantages of new instruments. This study describes and objectively evaluates the use of a robotized instrument using a force-sensing test platform. The test platform consists of 12 rings on a hypersensitive force sensor. Forty volunteers were recruited: the expert group included 20 laparoscopic experts and the novice group included 20 medical students in their 4th year without laparoscopic skills. The baseline of the two groups was identified using a conventional needle holder. Participants then repeated the test with the robotized needle holder after training. The maximum force and impulse of each ring were analyzed for each group. Institutional review board approval is not needed for this study. Significantly lower maximum force and impulse were observed in the expert group than in the novice group during the baseline test (all P < 0.05). After training, a significant difference remained in maximum force and impulse between the two groups using the robotized needle holder (all P < 0.05). Within each group, there was no difference in maximum force or impulse using the robotized needle holder after training compared to that on using the conventional needle holder (all P > 0.05). The maximum force and impulse recorded by a test platform can accurately identify participants' laparoscopic skill level. Six hours' training can ensure that experts master the use of the robotized needle holder, but this training session is too short for novices to improve their performance with a new instrument. The force-sensing test platform can reflect the suturing characteristics of users based on the skill level and is useful for laparoscopic suture training.

Analgesic Efficacy of Tramadol Compared With Meloxicam in Ducks (Cairina moschata domestica) Evaluated by Ground-Reactive Forces.

The purpose of this study was to determine the efficacy of tramadol and meloxicam in an induced, temporary arthritis model in ducks as assessed by ground-reactive forces measured by a pressure-sensitive walkway (PSW) system. Twelve ducks (Cairina moschata domestica) were randomly separated into 3 equal groups of 4 birds each: water control, tramadol treatment, and meloxicam treatment. Baseline measurements were collected by having all ducks walk along a 3-m-long PSW in a custom-built corral before anesthesia and induction of arthritis. Arthritis was induced in all groups through injection, under anesthesia, of a 3% monosodium urate (MSU) solution into the intertarsal joint. One hour after MSU injection, birds were orally gavage fed 1 mL of tap water (control), tramadol (30 mg/kg), or meloxicam (1 mg/kg). After treatments, all ducks were reevaluated on the PSW at 1, 2, 3, 4, 8, and 24 hours post-MSU injection. The difference in maximum force was significantly greater in the control group than in both the tramadol- (P = .006) and meloxicam-treated (P = .03) individuals. Post hoc comparisons revealed differences between control and treated birds occurred only at the 3- and 4-hour time points after administration. No differences were found in the absolute difference in maximum force between tramadol- and meloxicam-treated birds at any time point (P > .05). Results of this study support the hypothesis that tramadol (30 mg/kg PO) and meloxicam (1 mg/kg PO) improve certain objective variables in an induced arthritis model in ducks. Our findings also support studies in other avian species that determined that both tramadol and meloxicam are effective analgesic drugs in some birds.

دراسة مقارنة لبعض المتغيرات الكينيتيكية اثناء اداء الارسال القاطع بالوضعين (المتباعد والمتقارب) للقدمين في التنس

The research aimed at comparing some kinematical variables during tennis slice using closed and open stance on a footscan. The subjects were four registered tennis players in Kurdistan. The researchers used the footscan to measure some kinematical variables of the foot during the slice with two different stances; closed and open, to identify the differences between the two positions and which one is the best. The researchers concluded that there are significant differences in maximum force, maximum time, and impulse in favor of the open foot stance.&#x0D; Keywords: kinematical variables, open and closed stance, slice, lawn tennis.

The Impact of Simulator Size on Forces Generated in the Performance of a Defined Intracorporeal Suturing Task: A Pilot Study.

Background: In pediatric minimal access surgery, the operative domain may vary from that of an adult to that of a neonate. This study aimed to quantify the impact of decreased operative domain on forces generated in the performance of a defined intracorporeal suturing task. Methods: One hundred five participants performed a defined intracorporeal suturing task in small and large simulators. Time to task completion and force analysis parameters (FAPs = total, maximum, and mean forces in X, Y, and Z axes) were measured. Expertise level was assigned based on the number of laparoscopic cases. Outcomes were analyzed using paired sample t-tests, P value of <.05. Results: Time to task completion varied significantly for experts between adult and pediatric simulators but not for intermediates or novices. Total, maximum, and mean forces in the X ("side to side") axis were significantly greater in the larger laparoscopic simulator for all levels of expertise. In the Y axis ("in and out" movement) and Z axis ("up and down" movement), total and mean forces were higher in the adult simulator regardless of the level of expertise. Differences in maximum force between the adult and pediatric simulators in the Z axis ("up and down" movement) varied significantly for novices and intermediates but not for experts. Conclusion: Forces were greater, particularly in the side-to-side plane, in the larger simulator for participants of all levels in the performance of this defined intracorporeal suturing task. Further analysis will determine the reasons for and implications of the increased force parameters in the simulator of larger domain.

IPEG 2018The 27th Annual Congress for Endosurgery in ChildrenApril 11–14, 2018, Seattle, Washington

IPEG 2018The 27^th Annual Congress for Endosurgery in ChildrenApril 11–14, 2018, Seattle, Washington

Effects of turf and cleat footwear on plantar load distributions in adolescent American football players during resisted pushing

Metatarsal and midfoot injuries are common in American football. Footwear design may influence injury rates by altering plantar foot loading patterns in these regions. The purpose of this study was to determine the effect of cleat design on in-shoe plantar foot loading during a football-specific, resisted pushing task. Twenty competitive football players (age 14.7 ± 1.8 years, height 1.72 ± 0.10 m, and mass 71.8 ± 26.9 kg) completed three trials of pushing a weighted sled at maximal effort in a standard shoe (CLEAT) and artificial turf-specific shoe (TURF), with flexible in-shoe force measuring insoles. Repeated measures ANOVAs identified mean differences in maximum force and relative load under all regions of the foot. Results showed higher forces in the CLEAT under the medial (p < 0.001) and lateral (p = 0.004) midfoot, central (p = 0.007) and lateral (p < 0.001) forefoot, and lesser toes (p = 0.01), but lower forces in the hallux (p = 0.02) compared to the TURF shoe. Additionally, relative loading was higher in the CLEAT under the medial (p < 0.001) and lateral (p = 0.002) midfoot and lateral (p < 0.001) forefoot, but lower in the medial forefoot (p = 0.006) and hallux (p < 0.001) compared to the TURF shoe. The two shoes elicited distinct plantar loading profiles and may influence shoe selection decisions during injury prevention or rehabilitation practices.

Abnormal Cardiac Cross-Bridge Kinetics in a Troponin T ILE79ASN Transgenic Mouse Model

The missense mutation Ile79Asn in human cardiac troponin T (HcTnT-I79N) has been associated with phenotypic outcomes of familial hypertrophic cardiomyopathy, arrhythmias, and sudden cardiac death. Previous characterization of a transgenic mouse model bearing the HcTnT-I79N mutation, which expressed 52% HcTnT-I79N of total troponin T, demonstrated increased Ca2+ sensitivity of isometric force. However, little is known about the changes in cross-bridge kinetics, if any, that result from the mutation. This study investigates isometric force, sinusoidal stiffness and rate of tension redevelopment (kTR) of skinned papillary muscle fiber bundles at two sarcomere lengths (1.9 µm and 2.1 µm); cardiac muscle was isolated from the left ventricle of non-transgenic wild-type (WT) mice or transgenic mice bearing the HcTnT-I79N mutation. Sarcomere length (SL) was set at pCa8 using HeNe laser diffraction after the attachment points of each skinned fiber bundle were fixed with glutaraldehyde to minimize end compliance. Sinusoidal stiffness and kTR were obtained after recording steady-state isometric tension by oscillating the fiber bundle 0.2% of its relaxed length or by applying a ramped shortening followed by a quick re-stretch to original fiber bundle length, respectively. As previously reported, the HcTnT-I79N mutation resulted in increased Ca2+-sensitivity of isometric force although no difference in maximum force per cross-sectional area was observed. Length-dependent activation at the longer SL resulted in increased Ca2+-sensitivity of isometric force and sinusoidal stiffness, and decreased kTR for both WT and HcTnT-I79N. However, HcTnT-I79N exhibited faster kTR and greater sinusoidal stiffness at sub-maximum pCa (-log[Ca2+]) solutions compared to WT regardless of SL. These data indicate that HcTnT-I79N mutation, and SL, markedly influence not only the dynamics of individual regulatory units, but also the kinetics of cross-bridge cycling.

Effect of ligation method on maxillary arch force/moment systems for a simulated lingual incisor malalignment.

Introduction:The objectives of this study were to determine whether there is a difference in the magnitude of forces and moments produced by elastic ligation when compared to passive ligation, and whether these forces and moments propagate differently along the arch for the two ligation types. A lingual incisor malalignment was used in this study.Methods: The Orthodontic Simulator (OSIM) was used to quantify the three-dimensional forces and moments applied on the teeth given a lingually displaced incisor. A repeated measures MANOVA was performed to statistically analyze the data. Results: The interaction factor illustrated convincing evidence that there is a difference in maximum force and moment values for all outcome variables between ligation types considering all tooth positions along the arch. The mean differences for FX and FY between ligation types were found to be clinically significant, with values for elastic ligation consistently higher than passive ligation.Conclusion: It was found that the maximum forces and moments produced by elastic ligation are greater than those produced by passive ligation and that the magnitude of this difference for the mesiodistal and buccolingual forces is clinically relevant. Additionally, it was determined that elastic ligation causes forces and moments to propagate further along the arch than passive ligation for all outcome variables.

Histologic and biomechanical evaluation of a novel macroporous polytetrafluoroethylene knit mesh compared to lightweight and heavyweight polypropylene mesh in a porcine model of ventral incisional hernia repair

To evaluate the biocompatibility of heavyweight polypropylene (HWPP), lightweight polypropylene (LWPP), and monofilament knit polytetrafluoroethylene (mkPTFE) mesh by comparing biomechanics and histologic response at 1, 3, and 5 months in a porcine model of incisional hernia repair. Bilateral full-thickness abdominal wall defects measuring 4 cm in length were created in 27 Yucatan minipigs. Twenty-one days after hernia creation, animals underwent bilateral preperitoneal ventral hernia repair with 8 × 10 cm pieces of mesh. Repairs were randomized to Bard(®)Mesh (HWPP, Bard/Davol, http://www.davol.com), ULTRAPRO(®) (LWPP, Ethicon, http://www.ethicon.com), and GORE(®)INFINIT Mesh (mkPTFE, Gore & Associates, http://www.gore.com). Nine animals were sacrificed at each timepoint (1, 3, and 5 months). At harvest, a 3 × 4 cm sample of mesh and incorporated tissue was taken from the center of the implant site and subjected to uniaxial tensile testing at a rate of 0.42 mm/s. The maximum force (N) and tensile strength (N/cm) were measured with a tensiometer, and stiffness (N/mm) was calculated from the slope of the force-versus-displacement curve. Adjacent sections of tissue were stained with hematoxylin and eosin (H&E) and analyzed for inflammation, fibrosis, and tissue ingrowth. Data are reported as mean ± SEM. Statistical significance (P < 0.05) was determined using a two-way ANOVA and Bonferroni post-test. No significant difference in maximum force was detected between meshes at any of the time points (P > 0.05 for all comparisons). However, for each mesh type, the maximum strength at 5 months was significantly lower than that at 1 month (P < 0.05). No significant difference in stiffness was detected between the mesh types or between timepoints (P > 0.05 for all comparisons). No significant differences with regard to inflammation, fibrosis, or tissue ingrowth were detected between mesh types at any time point (P > 0.09 for all comparisons). However, over time, inflammation decreased significantly for all mesh types (P < 0.001) and tissue ingrowth reached a slight peak between 1 and 3 months (P = 0.001) but did not significantly change thereafter (P > 0.09). The maximum tensile strength of mesh in the abdominal wall decreased over time for HWPP, LWPP, and mkPTFE mesh materials alike. This trend may actually reflect inability to adequately grip specimens at later time points rather than any mesh-specific trend. Histologically, inflammation decreased with time (P = 0.000), and tissue ingrowth increased (P = 0.019) for all meshes. No specific trends were observed between the polypropylene meshes and the monofilament knit PTFE, suggesting that this novel construction may be a suitable alternative to existing polypropylene meshes.

Differences in viscosity and textural properties of selected barley cultivars as influenced by pearling and cooking

Viscosity and texture are important attributes not only in determining quality of barley but also in delivering health benefits of barley products. The present study aimed at investigating viscosity and textural properties of nine barley cultivars selected for their compositional differences and economic importance to Canada. The cultivars were pearled to varying degrees to obtain whole grain and three pearled barley fractions named commercial, pot and white pearl. Increasing pearling time resulted in higher peak, trough, setback and final viscosity compared with whole grain flours. The hulless cultivars tested, tended to have lower trough, final and setback viscosities than the hulled ones. The waxy cultivars exhibited higher breakdown viscosities than normal cultivars. Viscosity at 37 °C of two cooked barley cultivars having extreme glycemic index (GI) values were significantly different. In other words, cooked Celebrity cultivar (low GI) had higher viscosity than AC Klink cultivar (high GI). Significant differences in maximum force and shearing work were also observed between cultivars. On the contrary to viscosity, both force and work decreased as pearling time increased. The study showed that some barley cultivars such as Celebrity fractions may hold a promise for the development of barley as a functional food ingredient or rice substitute.

Aging-Related Differences in Maximum Force, Unloaded Velocity and Power of Human Leg Multi-Joint Movement

Background: Because many of our movements of daily living are multi-joint movements and lower limb performance decreases with aging, it is important to understand the influence of aging on muscle functions of lower limb multi-joint movements. Objective: To investigate aging-related differences in the maximum force, unloaded velocity and power of muscles that control leg multi-joint movements. Methods: 285 recreationally active men (n = 142) and women (n = 143) aged between 18 and 82 years volunteered for the study. Lower limb muscle function was measured with a servo-controlled dynamometer and the maximum isometric force (F_max), unloaded velocity (V_max) and power (P_max) were determined by the force-velocity and force-power relations. Results: With increasing age, F_max/body mass significantly declines in both men (r = –0.400, p <0.001) and women (r = –0.587, p < 0.001), while V_max/leg length does not change with age in either men (r = –0.033, p > 0.05) or women (r = –0.040, p > 0.05). P_max significantly declines with age in both men (r = –0.370, p < 0.001) and women (r = –0.446, p < 0.001). Conclusions: Aging does not have effects on the shortening velocity, although it causes a decrease in maximum force and power of leg multi-joint movements. This finding suggests that decreases in muscle force-generating capacity and power may primarily lead to the loss of mobility and a reduced capability of accelerating and decelerating the body mass during the movements in elderly individuals.

Pedobarographic Analysis Following Ponseti Treatment for Congenital Clubfoot

Current methods of treating congenital clubfeet provide high rates of functional outcomes. Despite the clinical outcomes, radiographic assessment suggests residual equinus deformity of the hindfoot. It is unclear whether these deformities result in abnormal foot-floor pressures and whether they correlate with clinical outcome. We evaluated 28 feet in 20 patients following Ponseti treatment for clubfoot by clinical and pedobarographic examination a mean of 33 months after removal of the last cast. The data were compared to age- and weight-matched normal subjects and to the unaffected foot in the unilaterally affected patients. Despite ankle range of motion of 30 degrees and a physiologic hindfoot valgus alignment in 19 cases, pedobarography suggested differences in maximum force, impulse, contact area, and peak pressure compared to normal subjects. Compared to the unaffected foot the only difference was reduced peak pressure over the medial hindfoot and forefoot with increased pressure over the lateral midfoot. Similar to radiographic abnormalities in studies on treated clubfeet with good functional outcome, pedobarographic analyses show differences compared to a control group. The value of pedobarographic analysis for predicting successful treatment of congenital clubfoot is questionable since it does not correlate with the clinical outcome in patients treated with the Ponseti method. Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Repeatability of physiotherapy chest wall vibrations applied to spontaneously breathing adults

Objective Chest wall vibrations are commonly used techniques that remain largely unquantified. In order to understand their effects, it is essential to measure the forces applied and their repeatability over time. This study investigated the repeatability of vibrations within and between test occasions. Design Test–retest repeatability study. Participants Eight physiotherapists applied vibrations to two healthy female adults. Intervention Physiotherapists performed seven vibrations on each subject, and measurements were repeated after 24 hours and 6 months. Outcome measures A force-sensing mat placed over the subject’s chest measured the amplitude, duration and force profile of each physiotherapist’s vibrations. Results There were no significant differences in maximum force, duration, frequency of oscillation or amplitude of oscillation within each set of seven chest wall vibrations, confirmed by repeated measures analysis of variance ( P = 0.42). However, there were wide variations in vibrations between different physiotherapists. Maximum forces ranged from 71 to 258 N, with frequency and amplitude of oscillation ranging from 3 to 11 Hz and 2 to 66 N, respectively. Duration of vibration ranged from 2 to 5 seconds. While there was no systematic bias in forces applied between test occasions, limits of agreement were wide following an interval of 24 hours (−34 to 58 N) and wider still after 6 months (−84 to 76 N). Conclusion Physiotherapists exhibit fine control of techniques, delivering vibrations uniformly within single test occasions. However, the variation between therapists and test occasions precludes accurate prediction of applied forces when treating stable patients on consecutive occasions. Furthermore, this study raises important questions about factors influencing the pattern and magnitude of forces applied, and the clinical and physiological effects of such variations.

Assessment of foot impairment in rheumatoid arthritis patients by dynamic pedobarography

Objectives Impaired foot function may jeopardize the mobility of patients with rheumatoid arthritis (RA). However, there are still no guidelines concerning the adequate early treatment of painful rheumatoid feet which do not yet require surgery. An assessment method for RA feet appears necessary in order to detect foot problems before functional limitations develop. Therefore, the aim of the present study was to evaluate the use of pedobarographic measurements for detecting changes in plantar loading characteristics and their relationship to foot pain in patients with RA. Methods One hundred and twelve patients with RA (55.0 ± 11.0 years of age) were divided into three groups according to their Health Assessment Questionnaire (HAQ) Score and compared to a control group of 20 healthy adults (CG). Thirty-six patients with good physical capacity belonged to group 1 (RA1; HAQ-score: 0–1.0), 38 patients with moderate capacity to group 2 (RA2; score: 1.1–2.0) and 38 patients with low capacity to group 3 (RA3; score: 2.1–3.0). Each patient's foot pain was clinically assessed. Pedobarography was used to analyze foot loading parameters while walking barefoot. Results In the forefoot, average pressures under the lateral forefoot were higher in RA1 patients than in RA2 patients and controls ( p < 0.05) despite an inconspicuous clinical examination of the foot in RA1 patients. RA1 patients also demonstrated higher plantar pressures than RA2 under the second metatarsal head ( p < 0.05). In contrast, no significant differences in maximum force could be demonstrated between patient groups. Furthermore, in RA3 patients with lower physical capacity, foot pain was increased as compared to RA1 and RA2 patients. Conclusion In RA patients, pedobarographic patterns show specific changes which characterize the level of functional capacity. In patients with foot involvement, pedobarographic measurements can be useful during the earlier stages of the disease, when clinical examination does not yet indicate the need for more aggressive treatment or orthopedic interventions.

CHANGE IN MECHANICAL PROPERTIES OF WHEAT STRAW DUE TO DECOMPOSITION AND MOISTURE

The mechanical properties of straw residues from cereal crops left on the soil surface are affected by thedecomposition rate and moisture during the inter-cropping period. We have examined the relationship between thephysical characteristics and mechanical properties of mature wheat straw as a function of decomposition and moisture.The mechanical properties were determined by shearing and bending tests. The ear internode had the lowest mass perunit length and the highest density because of its smaller diameter and stem wall thickness. The difference in maximumforce and energy required for failures between internodes is due to their mass per unit length and cross-sectional area.The higher Youngs modulus and maximum bending stress of the ear internode could be due to its higher proportion ofhemicelluloses. Bending strength decreased by 70% and shear strength by 80% with decomposition due to the loss ofmass and a change in biochemical composition (mainly loss of cellulose). Straw moisture had opposite effects on bendingand shearing: the maximum bending stress decreased by 54% and the shear stress increased by 83%. As bothdecomposition and moisture greatly modify the mechanical properties of straw, these two factors should be taken intoaccount in the management of straw after harvest.