Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

Background: Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge.

Methods: Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS), Flattened Heel Shoe (FHS), and Standard Heel Shoes (SHS).

Reliability of metatarsophalangeal and ankle joint torque measurements by an innovative device.

The toe flexor muscles maintain body balance during standing and provide push-off force during walking, running, and jumping. Additionally, they are important contributing structures to maintain normal foot function. Thus, weakness of these muscles may cause poor balance, inefficient locomotion and foot deformities.

Shoe collar height effect on athletic performance, ankle joint kinematics and kinetics during unanticipated maximum-effort side-cutting performance.

Side-step cutting manoeuvres comprise the coordination between planting and non-planting legs. Increased shoe collar height is expected to influence ankle biomechanics of both legs and possibly respective cutting performance. This study examined the shoe collar height effect on kinematics and kinetics of planting and non-planting legs during an unanticipated side-step cutting.

In-shoe plantar tri-axial stress profiles during maximum-effort cutting maneuvers.

Soft tissue injuries, such as anterior cruciate ligament rupture, ankle sprain and foot skin problems, frequently occur during cutting maneuvers. These injuries are often regarded as associated with abnormal joint torque and interfacial friction caused by excessive external and in-shoe shear forces. This study simultaneously investigated the dynamic in-shoe localized plantar pressure and shear stress during lateral shuffling and 45° sidestep cutting maneuvers.

Effect of tibial drill-guide angle on the mechanical environment at bone tunnel aperture after anatomic single-bundle anterior cruciate ligament reconstruction.

Purpose: The tibial drill-guide angle in anterior cruciate ligament (ACL) reconstruction influences the tunnel placement and graft-tunnel force, and is potentially associated with post-operative tunnel widening. This study aimed to examine the effect of the drill-guide angle on the stress redistribution at the tibial tunnel aperture after anatomic single-bundle ACL reconstruction.

Methods: A validated finite element model of human knee joint was used.

Kinetics of badminton lunges in four directions.

The lunge is the most fundamental skill in badminton competitions. Fifteen university-level male badminton players performed lunge maneuvers in four directions, namely, right-forward, left-forward, right-backward, and left-backward, while wearing two different brands of badminton shoes. The test compared the kinetics of badminton shoes in performing typical lunge maneuvers.

Biomechanical simulation of high-heeled shoe donning and walking.

Footwear serves to protect the foot in various activities, to enhance athletic performance in sports and in many cases to fulfill aesthetic and cultural needs of urban society. Most women like wearing high-heeled shoes (HHS) for the benefit of sensuous attractiveness, while foot problems are often associated. Computational modeling based on finite element (FE) analysis is a useful tool for deep understanding of foot and footwear biomechanics and incorporating footwear with foot in the model is the prerequisite.

Why do woodpeckers resist head impact injury: a biomechanical investigation.

Head injury is a leading cause of morbidity and death in both industrialized and developing countries. It is estimated that brain injuries account for 15% of the burden of fatalities and disabilities, and represent the leading cause of death in young adults. Brain injury may be caused by an impact or a sudden change in the linear and/or angular velocity of the head.

Effect of heel height on in-shoe localized triaxial stresses.

Abnormal and excessive plantar pressure and shear are potential risk factors for high-heeled related foot problems, such as forefoot pain, hallux valgus deformity and calluses. Plantar shear stresses could be of particular importance with an inclined supporting surface of high-heeled shoe. This study aimed to investigate the contact pressures and shear stresses simultaneously between plantar foot and high-heeled shoe over five major weightbearing regions: hallux, heel, first, second and fourth metatarsal heads, using in-shoe triaxial force transducers.

Development of a finite element model of female foot for high-heeled shoe design.

Background: Wearing high-heeled shoes may produce deleterious effects on the musculoskeletal system while elevation of the shoe heel with arch insole insert is used as a treatment strategy for plantar fasciitis. Due to limitations of the experimental approaches, direct measurements of internal stress/strain of the foot are impossible or invasive. This study aims at developing a finite element model for evaluating the biomechanical effects of high-heeled support on the ankle-foot complex.

Parametric design of pressure-relieving foot orthosis using statistics-based finite element method.

Custom-molded foot orthoses are frequently prescribed in routine clinical practice to prevent or treat plantar ulcers in diabetes by reducing the peak plantar pressure. However, the design and fabrication of foot orthosis vary among clinical practitioners and manufacturers. Moreover, little information about the parametric effect of different combinations of design factors is available.

Consequences of partial and total plantar fascia release: a finite element study.

Background: Plantar fasciotomy, a common operative procedure to relieve chronic heel pain, has been suggested to decrease foot arch stability. A systematic evaluation of the biomechanical consequences of partial or total plantar fascia release is essential to the understanding of the biomechanical rationale behind these operative procedures.

Methods: A geometrical detailed three-dimensional (3-D) finite element (FE) model of the human foot and ankle, incorporating geometrical and contact nonlinearities, was constructed by 3-D reconstruction of MR images.

Effect of sock on biomechanical responses of foot during walking.

Background: Except the plantar pressure and gross joint motion, we know little about the mechanical state of a foot during walking. This study aimed at investigating the effect of wearing socks with different frictional properties on plantar shear, which is a possible mechanical risk factor of foot lesion development.

Method: A 3-D finite element model for simulating the foot-sock-insole contact was developed to investigate the biomechanical effects of wearing socks with different combinations of frictional properties on the plantar foot contact.

Effect of Achilles tendon loading on plantar fascia tension in the standing foot.

Background: The plantar fascia, which is one of the major arch-supporting structures of the human foot, sustains high tensions during weight-bearing. A positive correlation between Achilles tendon loading and plantar fascia tension has been reported. Excessive stretching and tightness of the Achilles tendon are thought to be the risk factors of plantar fasciitis but their biomechanical effects on the plantar fascia have not been fully addressed.

A serrated jaw clamp for tendon gripping.

Mechanical testing of tendon and application of muscular tendon forces in cadaveric or animal studies requires the use of a clamp to hold the tendon rigidly at high loads without damaging it. Frozen type serrated clamp was able to achieve the objective but is less readily available and manageable because of its complex and massive configuration. In this study, a custom-made, serrated jaw clamp was fabricated.

Three-dimensional finite element analysis of the foot during standing--a material sensitivity study.

Information on the internal stresses/strains in the human foot and the pressure distribution at the plantar support interface under loading is useful in enhancing knowledge on the biomechanics of the ankle-foot complex. While techniques for plantar pressure measurements are well established, direct measurement of the internal stresses/strains is difficult. A three-dimensional (3D) finite element model of the human foot and ankle was developed using the actual geometry of the foot skeleton and soft tissues, which were obtained from 3D reconstruction of MR images.

A 3-dimensional finite element model of the human foot and ankle for insole design.

Objective: To investigate the effect of material stiffness of flat and custom-molded insoles on plantar pressures and stress distribution in the bony and ligamentous structures during balanced standing.

Design: A 3-dimensional (3-D) finite element model of the human ankle-foot complex and a custom-molded insole were developed from 3-D reconstruction of magnetic resonance images and surface digitization. The distal tibia and fibula, together with 26 foot bones and 72 major ligaments and the plantar fascia, were embedded in a volume of soft tissues.

Effects of plantar fascia stiffness on the biomechanical responses of the ankle-foot complex.

Background: The plantar fascia is one of the major stabilizing structures of the longitudinal arch of human foot, especially during midstance of the gait cycle. Knowledge of its functional biomechanics is important for establishing the biomechanical rationale behind different rehabilitation, orthotic and surgical treatment of plantar fasciitis. This study aims at quantifying the biomechanical responses of the ankle-foot complex with different plantar fascia stiffness.

Biomechanical responses of the intervertebral joints to static and vibrational loading: a finite element study.

Objective: This study was performed to investigate the time-dependent responses of the intervertebral joint to static and vibrational loads.

Design: A poroelastic finite element model was established to analyse the fluid flow, stress distribution and deformation of the intervertebral disc.

Background: Long-term exposure to whole body vibration is highly associated with disc degeneration and low back pain.