Search Results

You are looking at 1 - 10 of 106 items for :

Clear All
Restricted access

Fabian Mager, Jim Richards, Malika Hennies, Eugen Dötzel, Ambreen Chohan, Alex Mbuli and Felix Capanni

Forefoot stiffness has been shown to influence joint kinematics and kinetics. Willwacher et al 1 found that changes in the stiffness of the metatarsophalangeal joint have a bearing on power generation, push-off duration, and anterior shift of the center of pressure in the second half of stance

Restricted access

Wing-Kai Lam, Winson Chiu-Chun Lee, Wei Min Lee, Christina Zong-Hao Ma and Pui Wah Kong

Previous studies have shown that shoe bending stiffness was related to changes in joint kinematics and kinetics as well as athletic performance. 1 Increasing forefoot bending stiffness of a shoe, which can be achieved by inserting a forefoot plate or increasing the midsole hardness, has the

Restricted access

Wataru Kawakami, Makoto Takahashi, Yoshitaka Iwamoto and Koichi Shinakoda

previous studies investigated kinematic behaviors of feet affected by hallux valgus using multisegment foot models. 6 , 14 , 15 However, these studies used multisegment foot models defined by the shank, rearfoot, forefoot, and hallux without definition of the midfoot. Furthermore, although several

Restricted access

Todd A. Evans, Sharon N. Domorski, Wayne J. Sebastianelli, Margot Putukian and Jay N. Hertel

Idiopathic forefoot pain, often termed metatarsalgia, is a common complaint among running athletes. Whereas several causes are often included in the differential diagnosis, Freiberg’s infraction is rarely considered. The signs and symptoms present with Freiberg’s infraction however, can mimic those present with more common forefoot injuries. The article presents the case of a female Division-I college soccer player who developed and was successfully treated for bilateral Freiberg’s infraction. Her initial complaint of unilateral forefoot pain, induced only by vigorous running, progressed to intolerable bilateral forefoot pain with light exercise. Conservative treatment was unsuccessful, and therefore surgery was required to enable her continued athletic participation. As with all weight-bearing joints, clinicians need to be aware of the potential for progressive degenerative changes at the metatarsal heads and the steps used in the evaluation and subsequent treatment of Freiberg’s infraction

Restricted access

Carrie A. Laughton, Irene McClay Davis and Joseph Hamill

The main purpose of this study was to investigate the effects of both strike pattern (forefoot vs. rearfoot strike pattern) and orthotic intervention on shock to the lower extremity. Semi-rigid orthotic devices were manufactured for 15 injury-free recreational runners. Tibial accelerometry, ground reaction force, and 3D kinematic data were collected on their right leg in four conditions: forefoot strike (FFS) and rearfoot strike (RFS) with and without orthotics. Two-way repeated-measures analysis of variance tests were used to assess the effects of strike pattern and orthotic intervention on tibial acceleration; angular excursions of the ankle and knee; ground reaction force (GRF) vertical and anteroposterior peaks and load rates; and ankle, knee, and leg stiffness. There was a significant increase in tibial acceleration for the FFS pattern compared to the RFS pattern. This may be explained in part by the significantly greater peak vertical GRF, peak anteroposterior GRF, anteroposterior GRF load rates, knee stiffness, and leg stiffness found in the FFS pattern compared to the RFS pattern. Tibial acceleration and rearfoot eversion excursions were similar between the orthotic and no-orthotic conditions. Knee flexion excursion and average GRF vertical load rates were significantly decreased while dorsiflexion excursion and knee stiffness were significantly increased in the orthotic condition. No significant interactions were found between strike pattern and orthotic condition for any variables assessed.

Restricted access

Dorsey S. Williams III, Irene S. McClay and Kurt T. Manal

Runners are sometimes advised to alter their strike pattern as a means of increasing performance or in response to injury. The purpose of this study was to compare lower extremity mechanics of rearfoot strikers (RFS), who were instructed to run with a forefoot strike pattern (CFFS) to those of a preferred forefoot striker (FFS). Three-dimensional mechanics of 9 FFS and 9 CFFS were evaluated. Peak values for most kinematic and kinetic variables and all patterns of movement were not found to be statistically different between CFFS and FFS. Only peak vertical ground reaction force and peak ankle plantarflexion moment were found to be significantly lower (p ≤ .05) in the CFFS group. This suggests that RFS are able to assume a FFS pattern with very little practice that is very similar to that of a preferred FFS. The impact of changing one's strike pattern on injury risk and running performance needs further study.

Restricted access

Marianne J. R. Gittoes and David G. Kerwin

This study aimed to gain insight into the individual and interactive effects of segmental mass proportions and coupling properties on external loading in simulated forefoot landings. An evaluated four-segment wobbling mass model replicated forefoot drop landings (height: 0.46 m) performed by two subjects. A comparison of the peak impact forces (GFzmax) produced during the evaluated landing and further simulated landings performed using modified (±5% perturbation) mass proportions and coupling properties was made. Independent segmental mass proportion changes, particularly in the upper body, produced a prominent change in GFzmax of up to 0.32 bodyweight (BW) whereas independent mass coupling stiffness and damping alterations had less effect on GFzmax (change in GFzmax of up to 0.18 BW). When combining rigid mass proportion reductions with damping modifications, an additional GFzmax attenuation of up to 0.13 BW was produced. An individual may be predisposed to high loading and traumatic and overuse injury during forefoot landings owing to their inherent inertia profile. Subject-specific neuromuscular modifications to mass coupling properties may not be beneficial in overriding the increased forces associated with larger rigid mass proportions.

Restricted access

Marianne J. R. Gittoes, David G. Kerwin and Mark A. Brewin

The impact loads experienced in landing may be influenced by the joint kinematic strategy used. This study aimed to enhance the understanding of the sensitivity of impact loading to the timing of joint kinematic strategies in simulated forefoot landings. Coordinate and force data of drop landings were used to initiate, drive, and evaluate a wobbling mass model. Ankle, knee, and hip joint angle profile timings were modified in the simulated motions. Changes to the timing of the ankle and knee joint angle profiles were associated with substantial changes in the peak vertical ground reaction force (GFzmax) of up to 3.9 body-weights (BW) and 1.5 BW, respectively, whereas loading was less sensitive to temporal changes in the hip joint strategy. Accentuated impact loads incurred by a modified knee flexion action may be explained by the need to maintain an ordered and controlled load attenuation strategy. Individual strategies and external and joint reaction forces should be considered for developing insight into loading in impact landings.

Restricted access

Jana Fleischmann, Guillaume Mornieux, Dominic Gehring and Albert Gollhofer

Sideward movements are associated with high incidences of lateral ankle sprains. Special shoe constructions might be able to reduce these injuries during lateral movements. The purpose of this study was to investigate whether medial compressible forefoot sole elements can reduce ankle inversion in a reactive lateral movement, and to evaluate those elements’ influence on neuromuscular and mechanical adjustments in lower extremities. Foot placement and frontal plane ankle joint kinematics and kinetics were analyzed by 3-dimensional motion analysis. Electromyographic data of triceps surae, peroneus longus, and tibialis anterior were collected. This modified shoe reduced ankle inversion in comparison with a shoe with a standard sole construction. No differences in ankle inversion moments were found. With the modified shoe, foot placement occurred more internally rotated, and muscle activity of the lateral shank muscles was reduced. Hence, lateral ankle joint stability during reactive sideward movements can be improved by these compressible elements, and therefore lower lateral shank muscle activity is required. As those elements limit inversion, the strategy to control inversion angles via a high external foot rotation does not need to be used.

Restricted access

Stephen C. Cobb, Mukta N. Joshi and Robin L. Pomeroy

In-vitro and invasive in-vivo studies have reported relatively independent motion in the medial and lateral forefoot segments during gait. However, most current surface-based models have not defined medial and lateral forefoot or midfoot segments. The purpose of the current study was to determine the reliability of a 7-segment foot model that includes medial and lateral midfoot and forefoot segments during walking gait. Three-dimensional positions of marker clusters located on the leg and 6 foot segments were tracked as 10 participants completed 5 walking trials. To examine the reliability of the foot model, coefficients of multiple correlation (CMC) were calculated across the trials for each participant. Three-dimensional stance time series and range of motion (ROM) during stance were also calculated for each functional articulation. CMCs for all of the functional articulations were ≥ 0.80. Overall, the rearfoot complex (leg–calcaneus segments) was the most reliable articulation and the medial midfoot complex (calcaneus–navicular segments) was the least reliable. With respect to ROM, reliability was greatest for plantarflexion/dorsiflexion and least for abduction/adduction. Further, the stance ROM and time-series patterns results between the current study and previous invasive in-vivo studies that have assessed actual bone motion were generally consistent.