Hayley Vincent

Influence of Different Hip Joint Centre Locations on Hip and Knee Joint Kinetics and Kinematics During the Squat

Abstract Identification of the hip joint centre (HJC) is important in the biomechanical examination of human movement. However, there is yet to be any published information regarding the influence of different HJC locations on hip and knee joint kinetics during functional tasks. This study aimed to examine the influence of four different HJC techniques on 3- D hip and knee joint kinetics/kinematics during the squat. Hip and knee joint kinetics/kinematics of the squat were obtained from fifteen male participants using an eight camera motion capture system. The 3-D kinetics/kinematics of the squat were quantified using four hip joint centre estimation techniques. Repeated measures ANOVAs were used to compare the discrete parameters as a function of each HJC location. The results show that significant differences in joint angles and moment parameters were evident at both the hip and knee joint in the coronal and transverse planes. These observations indicate that when calculating non-sagittal joint kinetics/kinematics during the squat, researchers should carefully consider their HJC method as it may significantly affect the interpretation of their data.

Effects of conventional and minimalist footwear on patellofemoral and Achilles tendon kinetics during netball specific movements

Netball is a physically demanding sport that is associated with a high incidence of chronic injuries. Currently there is a trend towards the utilisation of minimalist footwear in netball players as opposed to more conventional netball trainers. The current investigation aimed to examine the effects of netball specific and minimalist footwear on patellofemoral and Achilles tendon loads during netball specific motions. Fifteen female netballers performed both run and cut movements when wearing conventional netball footwear and also a minimalist trainer. Kinematics of the lower extremities were quantified using a motion analysis system alongside ground reaction force information which was obtained using a force platform. Patellofemoral force (PTF), patellofemoral pressure (PP) and Achilles tendon forces (ATF) were quantified using predictive methods and examined between footwear using repeated measures ANOVA. The results indicate that patellofemoral loads (run – PTF: netball specific = 5.56 / minimalist = 4....

Acute exposure to foot orthoses affects joint stiffness characteristics in recreational male runners

Commercially available foot orthoses are advocated for the treatment of chronic running injuries, such as patellofemoral pain, yet the mechanisms behind their effects are not well understood. This study aimed to examine the limb and joint stiffness characteristics when running with and without orthotics. Twelve recreational runners ran at 4.0 m/s. Limb stiffness was obtained using a spring-mass model of running by dividing the peak vertical ground reaction force (GRF) by the amount of limb compression. Knee and ankle joint stiffness’s were calculated by dividing the peak sagittal plane joint moment by the joint angular excursion. Differences between orthotic and non-orthotic running conditions were contrasted using paired samples t-tests. The results indicate that both peak knee extensor moment (orthotic = 2.74±0.57 and no-orthotic = 3.12±0.62 Nm/kg) and knee stiffness (orthotic = 5.56±1.08 and no-orthotic = 6.47±1.40 Nm/kg rad) were significantly larger when running without orthotics. This study may give...

Modelling of Muscle Force Distributions During Barefoot and Shod Running.

Abstract Research interest in barefoot running has expanded considerably in recent years, based around the notion that running without shoes is associated with a reduced incidence of chronic injuries. The aim of the current investigation was to examine the differences in the forces produced by different skeletal muscles during barefoot and shod running. Fifteen male participants ran at 4.0 m·s-1 (± 5%). Kinematics were measured using an eight camera motion analysis system alongside ground reaction force parameters. Differences in sagittal plane kinematics and muscle forces between footwear conditions were examined using repeated measures or Freidman’s ANOVA. The kinematic analysis showed that the shod condition was associated with significantly more hip flexion, whilst barefoot running was linked with significantly more flexion at the knee and plantarflexion at the ankle. The examination of muscle kinetics indicated that peak forces from Rectus femoris, Vastus medialis, Vastus lateralis, Tibialis anterior were significantly larger in the shod condition whereas Gastrocnemius forces were significantly larger during barefoot running. These observations provide further insight into the mechanical alterations that runners make when running without shoes. Such findings may also deliver important information to runners regarding their susceptibility to chronic injuries in different footwear conditions.