Les gonalgies et les aponévrosites plantaires représentent la majorité des motifs de consultations d’un cabinet de podologie. Les patients souffrant de ces pathologies ressentent des douleurs au niveau du genou ou du pied qui peuvent être invalidantes. Bien que le port d’orthèses plantaires représente un traitement conservateur efficace, la prescription de ce traitement repose sur une connaissance empirique des effets de ce dernier. Le but de ce travail était donc d’étudier les effets des semelles orthopédiques à dominante biomécanique (modifiant la posture) ou proprioceptive (stimulant les capteurs de la sole plantaire) sur les modifications de la stratégie neurale chez les patients souffrant de ces pathologies et de déterminer quels pouvaient être les liens avec la diminution de la douleur ressentie. Pour cela, nous avons procédé à une évaluation de la douleur, un examen de la marche, un examen stabilométrique et des enregistrements électrophysiologiques (réflexes mesurés au repos et lors d’une contraction musculaire volontaire). L’évolution de ces différents paramètres a été mesurée après trois, six et neuf semaines de port d'orthèses plantaires. Les résultats obtenus ont été comparés à ceux recueillis chez des patients témoins indemnes de toute pathologie.Même si les résultats obtenus lors de ces études ne sont pas aussi concluants que nous l’aurions souhaité et que de nombreuses questions restent encore en suspend, ce travail a permis toutefois d’ouvrir au domaine de la podologie un champ de recherche jusque-là peu ou pas exploré. / Knee pain and plantar fasciitis represent most of the reasons for consultation of a podiatrist. Patients with these pathologies experience knee or foot pain that can be disabling. Although the use of foot orthoses is an effective conservative treatment, its prescription is based on an empirical knowledge of its effects. The aim of this study was to investigate the effects of foot orthoses based on biomechanical (modifying the posture) or proprioceptive (stimulating sensors of the plantar sole) principles on neural strategy changes in suffering patients and to determine the links with the decrease in perceived pain. For this, we performed a pain assessment, walking and stabilometric examination and electrophysiological recordings (reflexes measured at rest and during voluntary muscle contraction). The evolution of these different parameters was measured after three, six and nine weeks of wearing foot orthoses. The results obtained were compared with those obtained in control patients free from any pathology.Although the results of these studies are not as conclusive as we would have liked and many questions remain unresolved, this work has opened up to the podiatry a field of research until then little or not explored.

La course d'ultra-trail en montagne provoque de nombreuses altérations d'ordre biomécaniques, physiologiques, neuro-musculaires, posturales et psychologiques qui peuvent engendrer certaines blessures. Cependant, assez peu d'études se sont intéressées aux modifications que peuvent subir les pieds. C'est dans ce cadre que nous avons réalisé 3 études. La première effectuée auprès de 10 coureurs a montré que les avants-pieds s'élargissent et la pression plantaire sous l'avant-pied augmente à partir de la mi-distance d'une épreuve d'ultra-trail de 170 km (UTMB®). La surpression sous l'avant-pied qui est due au déplacement vers l'avant du centre de pression, est susceptible d'accroitre le risque de fracture de fatigue des métatarses. Ces modifications qui ont été observées jusqu'à la fin de la compétition sont probablement liées à la fatigue des sujets. Pour contrecarrer ces modifications, nous avons proposé d'utiliser des semelles orthopédiques moulées comportant chacune une barre rétro capitale (BRC) placée en arrière des têtes métatarsiennes. La 2ème étude réalisée chez 48 coureurs a montré que cet élément orthopédique permet lors du maintien de la posture debout de diminuer les pressions plantaires sous les avants-pieds, de reculer le centre de pression, mais aussi les centres articulaires de la hanche, des épaules et de la tête. La 3ème étude avait pour objectif d'évaluer chez 10 coureurs à pieds l'effet immédiat, à court terme (après 4 semaines) et moyen terme (après 12 semaines) du port des semelles BRC sur la répartition des pressions plantaires et la cinématique articulaire. Un groupe contrôle de taille égale a utilisé pendant la même période des semelles moulées qui ne comportaient aucun élément orthopédique. Cette étude longitudinale a montré que les pressions plantaires sous les têtes métatarsiennes étaient réduites immédiatement avec le port des semelles BRC. Après 4 semaines, cette réduction s'accentuait et l'angle de flexion de la cheville était augmenté lors de l'appui. Après 12 semaines, l'extension maximale du genou était augmentée et la plupart de ces modifications étaient aussi observées même si les sujets utilisent des semelles plates. Aucune variable n'a été modifiée chez les sujets du groupe contrôle. En ce qui concerne les applications pratiques de ces travaux de thèse, au regard de nos résultats, nous pouvons conseiller aux coureurs de longue distance soufrant de douleur au niveau de l'avant-pied de choisir des chaussures un peu plus larges et, d'utiliser des semelles orthopédiques BRC pour réduire la pression sous l'avant-pied. / Mountain Ultra Marathon is causing many biomechanical, physiological, neuromuscular, postural and psychological alterations which can lead to certain injuries. However, there are few studies has been focused on the feet. In this context, we conducted three original studies. The first one, performed with 10 runners has shown that the front feet width and the plantar pressure under the forefoot has increased from the mid-distance of a 170km ultra-trail race (UTMB®). The overpressure under the forefoot is due to the forward displacement of the center of pressure which may increase the risk of stress fracture of the metatarsals. These changes that were observed until the end of the competition are probably related to the increase of muscular fatigue of the subjects. In opposition of these changes, we proposed to use moulded orthopaedic insoles that comprising a metatarsal retro-capital bar (MRCB) placed behind the metatarsal heads. The second study carried out in 48 runners has shown that this MRCB element allows to reduce the plantar pressures under the front feet during the standing support by moving backward the center of pressure, and also the hip, the shoulders and the head. The objective of the third study was to evaluate the immediate, short-term (after 4 weeks) and medium-term (after 12 weeks) effect of wearing MRCB insoles on plantar pressure distribution and joint kinematics during running with 10 runners. A similar control group of equal size used during the same period of training moulded insoles without orthopaedic element. This longitudinal study showed that the plantar pressures under the metatarsal heads were reduced immediately with wearing MRCB soles. After 4 weeks, this reduction was accentuated and the ankle's angle of flexion was increased during the stride support. After 12 weeks, the maximum knee extension was increased and most of these changes described aboved were also observed even if the subjects used flat insoles. Any significant changes have been observed in the control group whatever the test period. Regard to these results, we can advise long-distance runners that suffer of pain in the forefoot region to choose slightly larger shoes and to use MRCB orthopaedic insoles to reduce pressure under the forefoot.

Os objetivos desta pesquisa consistiram em contribuir para o projeto das órteses, realizar a análise cinemática do movimento de flexão/extensão do cotovelo, além de avaliar qualitativamente a independência na execução de atividades de vida diária e o ganho neurológico decorrente de um período de 6 meses de estimulação elétrica neuro-muscular (EENM). Participaram desta pesquisa oito tetraplégicos e um sujeito saudável. As órteses foram projetadas e os primeiros protótipos desenvolvidos. As avaliações cinemáticas foram realizadas durante dez tentativas do movimento de flexão/extensão do cotovelo em diferentes atividades. As avaliações qualitativas foram realizadas com os Protocolos ASIA e FIM. As órteses mostraram eficácia e funcionalidade. A avaliação cinemática mostrou que durante os movimentos com EENM houve repetibilidade, mudança no tipo de onda (de pico para retangular) e aumento do tempo de execução da atividade, comparado ao movimento voluntário. Com preensão de objeto e adição de cargas, houve alteração no padrão cinemático do movimento para a maioria dos pacientes, que indica insegurança em relação a preensão, fraqueza muscular, bem como, perturbação e incoordenação do movimento; em outros casos, houve aumento da amplitude de onda e predominância do tipo em rampa durante a EENM, o que possivelmente indica ação sinergista. Os resultados dos protocolos ASIA e FIM mostraram ganho neurológico e aumento no índice de independência funcional, para a maioria dos pacientes, decorrentes dos efeitos terapêuticos da EENM / The objectives of this research consisted of contributing for the orthosis project, to asses the knematics of the elbow flexion and extension, besides the qualitative evaluations of the independence to perform activities of daily living and neurological improvements due to a period of six months of neuromuscular electrical stimulation (NMES). Eight tetraplegics and one healthy subject participated in this study. The orthosis was projected and the first prototypes were developed. The kinematic assessment consisted of ten trials of elbow flexion and extension in different activities. The qualitative evaluations were accomplished with the ASIA and FIM Protocols. The orthosis showed effectiveness and functionality. The kinematics analysis showed that during movements with NMES there was repeatability, change in the wave form (peak to rectangular) and increase in time of performed trials, compared to the voluntary movement. With prehension of object and addition of loads, there was alteration in the kinematics pattern of the movement for most of the patients, which indicates insecurity during the prehension, muscular weakness, as well as perturbation and movement incoordination. On the others cases, there were higher wave amplitudes and wave forms mostly in ramp during NMES, which possibly indicates synergist action. The results of the ASIA e FIM Protocols showed neurological improvements and also in the index of functional independence for most of the patients due to the therapeutic effects of NMES

The ankle sprain is a common injury in basketball. A mechanism for this injury occurs when landing improperly from a jump. The concept of wedge and flare designs in shoes is (1) to offer benefit in reducing the potential for an ankle sprain while (2) not hindering performance or usability concerning basketball movements that are needed for successful play. The purpose was to take conceptual designs of the wedge and flare through an iterative design process. Therefore, the objectives were to fabricate shoe prototypes with these conceptual designs, to test the performance of these prototypes, and to develop the next iteration of design based upon the results of testing. The results of this design process are discussed.

Os objetivos desta pesquisa consistiram em contribuir para o projeto das órteses, realizar a análise cinemática do movimento de flexão/extensão do cotovelo, além de avaliar qualitativamente a independência na execução de atividades de vida diária e o ganho neurológico decorrente de um período de 6 meses de estimulação elétrica neuro-muscular (EENM). Participaram desta pesquisa oito tetraplégicos e um sujeito saudável. As órteses foram projetadas e os primeiros protótipos desenvolvidos. As avaliações cinemáticas foram realizadas durante dez tentativas do movimento de flexão/extensão do cotovelo em diferentes atividades. As avaliações qualitativas foram realizadas com os Protocolos ASIA e FIM. As órteses mostraram eficácia e funcionalidade. A avaliação cinemática mostrou que durante os movimentos com EENM houve repetibilidade, mudança no tipo de onda (de pico para retangular) e aumento do tempo de execução da atividade, comparado ao movimento voluntário. Com preensão de objeto e adição de cargas, houve alteração no padrão cinemático do movimento para a maioria dos pacientes, que indica insegurança em relação a preensão, fraqueza muscular, bem como, perturbação e incoordenação do movimento; em outros casos, houve aumento da amplitude de onda e predominância do tipo em rampa durante a EENM, o que possivelmente indica ação sinergista. Os resultados dos protocolos ASIA e FIM mostraram ganho neurológico e aumento no índice de independência funcional, para a maioria dos pacientes, decorrentes dos efeitos terapêuticos da EENM / The objectives of this research consisted of contributing for the orthosis project, to asses the knematics of the elbow flexion and extension, besides the qualitative evaluations of the independence to perform activities of daily living and neurological improvements due to a period of six months of neuromuscular electrical stimulation (NMES). Eight tetraplegics and one healthy subject participated in this study. The orthosis was projected and the first prototypes were developed. The kinematic assessment consisted of ten trials of elbow flexion and extension in different activities. The qualitative evaluations were accomplished with the ASIA and FIM Protocols. The orthosis showed effectiveness and functionality. The kinematics analysis showed that during movements with NMES there was repeatability, change in the wave form (peak to rectangular) and increase in time of performed trials, compared to the voluntary movement. With prehension of object and addition of loads, there was alteration in the kinematics pattern of the movement for most of the patients, which indicates insecurity during the prehension, muscular weakness, as well as perturbation and movement incoordination. On the others cases, there were higher wave amplitudes and wave forms mostly in ramp during NMES, which possibly indicates synergist action. The results of the ASIA e FIM Protocols showed neurological improvements and also in the index of functional independence for most of the patients due to the therapeutic effects of NMES

L’articulation du genou est sujette à de nombreuses pathologies pouvant entraîner des instabilités. Les démarches thérapeutiques incluent communément le port d’orthèses, dans le but de stabiliser ou limiter les mouvements articulaires. Malgré une forte prescription, l’évaluation de ces dispositifs manque encore de standardisation.En lien avec des médecins et des industriels, différents outils ont été développés pour évaluer leur efficacité biomécanique. Un modèle éléments finis d’un membre inférieur appareillé a notamment permis d’étudier l’effet de divers paramètres de conception d’une genouillère sur les pressions exercées et sur sa capacité à limiter un mouvement pathologique. Ce modèle a servi à valider un banc de test pouvant contribuer à l’innovation et la certification. Afin d’appréhender les problèmes de confort, le glissement des orthèses sur la peau a été caractérisé par des mesures de champ. Enfin, leurs actions in vivo ont été mesurées à l’aide d’un arthromètre sur des patients présentant une laxité.Les résultats mettent en évidence l’importance des caractéristiques techniques des orthèses et la spécificité du patient sur leurs niveaux d’action. Ainsi, il est possible de cibler des pathologies en jouant sur certains facteurs. Cependant, comparé aux structures de stabilisation passive (ligaments), le rôle des orthèses s’avère limité aux conditions de faibles sollicitations mécaniques. Néanmoins, leurs effets actifs et proprioceptifs (contrôle neuro-musculaire) seraient également à considérer.Ces outils s’avèrent complémentaires ; ils ouvrent la voie à des démarches d’évaluation standardisées et pourront également aider au développement de nouveaux produits. / The knee joint is vulnerable to various injuries and degenerative conditions, potentially leading to instabilities. Usual treatments involve orthoses, which are medical devices aimed at supporting, aligning or immobilizing the joint. However, the evaluation of these devices lacks standardisation despite high prescription and demand.In relation with clinicians and manufacturers, different tools were developed to assess their biomechanical efficiency. Firstly, a finite element analysis (FEA) of a braced lower limb was used to investigate the effects of brace design on its ability to prevent a pathological motion and understand the force transfer mechanisms. This model provided a basis to validate an experimental surrogate limb with the aim of providing an innovation and certification tool for manufacturers. In an attempt to apprehend comfort issues, full-field measurements of brace migration and FEA of contact pressures were performed. Finally, their in vivo actions were measured on ACL-deficient patients using a laxity testing device.Results highlight the importance of brace technical characteristics and patient-specificity on characterized levels of action and comfort. Furthermore, some key design factors allowed to target devices to particular pathologies. However, when compared to in vivo passive stabilizing structures (ligaments), the efficiency of knee braces was restrained to low load conditions. Nevertheless, these devices may also have a substantial effect on active stabilizing mechanisms such as neuro-muscular control.These tools were found to be complementary and may hopefully pave the way to a standardised procedure for evaluating and developing new designs.

In children, joint hypermobility (typified by structural instability of joints) manifests clinically as neuro-muscular and musculo-skeletal conditions and conditions associated with development and organization of control of posture and gait (Finkelstein, 1916; Jahss, 1919; Sobel, 1926; Larsson, Mudholkar, Baum and Srivastava, 1995; Murray and Woo, 2001; Hakim and Grahame, 2003; Adib, Davies, Grahame, Woo and Murray, 2005:). The process of control of the relative proportions of joint mobility and stability, whilst maintaining equilibrium in standing posture and gait, is dependent upon the complex interrelationship between skeletal, muscular and neurological function (Massion, 1998; Gurfinkel, Ivanenko, Levik and Babakova, 1995; Shumway-Cook and Woollacott, 1995). The efficiency of this relies upon the integrity of neuro-muscular and musculo-skeletal components (ligaments, muscles, nerves), and the Central Nervous System’s capacity to interpret, process and integrate sensory information from visual, vestibular and proprioceptive sources (Crotts, Thompson, Nahom, Ryan and Newton, 1996; Riemann, Guskiewicz and Shields, 1999; Schmitz and Arnold, 1998) and development and incorporation of this into a representational scheme (postural reference frame) of body orientation with respect to internal and external environments (Gurfinkel et al., 1995; Roll and Roll, 1988). Sensory information from the base of support (feet) makes significant contribution to the development of reference frameworks (Kavounoudias, Roll and Roll, 1998). Problems with the structure and/ or function of any one, or combination of these components or systems, may result in partial loss of equilibrium and, therefore ineffectiveness or significant reduction in the capacity to interact with the environment, which may result in disability and/ or injury (Crotts et al., 1996; Rozzi, Lephart, Sterner and Kuligowski, 1999b). Whilst literature focusing upon clinical associations between joint hypermobility and conditions requiring therapeutic intervention has been abundant (Crego and Ford, 1952; Powell and Cantab, 1983; Dockery, in Jay, 1999; Grahame, 1971; Childs, 1986; Barton, Bird, Lindsay, Newton and Wright, 1995a; Rozzi, et al., 1999b; Kerr, Macmillan, Uttley and Luqmani, 2000; Grahame, 2001), there has been a deficit in controlled studies in which the neuro-muscular and musculo-skeletal characteristics of children with joint hypermobility have been quantified and considered within the context of organization of postural control in standing balance and gait. This was the aim of this project, undertaken as three studies. The major study (Study One) compared the fundamental neuro-muscular and musculo-skeletal characteristics of 15 children with joint hypermobility, and 15 age (8 and 9 years), gender, height and weight matched non-hypermobile controls. Significant differences were identified between previously undiagnosed hypermobile (n=15) and non-hypermobile children (n=15) in passive joint ranges of motion of the lower limbs and lumbar spine, muscle tone of the lower leg and foot, barefoot CoP displacement and in parameters of barefoot gait. Clinically relevant differences were also noted in barefoot single leg balance time. There were no differences between groups in isometric muscle strength in ankle dorsiflexion, knee flexion or extension. The second comparative study investigated foot morphology in non-weight bearing and weight bearing load conditions of the same children with and without joint hypermobility using three dimensional images (plaster casts) of their feet. The preliminary phase of this study evaluated the casting technique against direct measures of foot length, forefoot width, RCSP and forefoot to rearfoot angle. Results indicated accurate representation of elementary foot morphology within the plaster images. The comparative study examined the between and within group differences in measures of foot length and width, and in measures above the support surface (heel inclination angle, forefoot to rearfoot angle, normalized arch height, height of the widest point of the heel) in the two load conditions. Results of measures from plaster images identified that hypermobile children have different barefoot weight bearing foot morphology above the support surface than non-hypermobile children, despite no differences in measures of foot length or width. Based upon the differences in components of control of posture and gait in the hypermobile group, identified in Study One and Study Two, the final study (Study Three), using the same subjects, tested the immediate effect of specifically designed custom-made foot orthoses upon balance and gait of hypermobile children. The design of the orthoses was evaluated against the direct measures and the measures from plaster images of the feet. This ascertained the differences in morphology of the modified casts used to mould the orthoses and the original image of the foot. The orthoses were fitted into standardized running shoes. The effect of the shoe alone was tested upon the non-hypermobile children as the non-therapeutic equivalent condition. Immediate improvement in balance was noted in single leg stance and CoP displacement in the hypermobile group together with significant immediate improvement in the percentage of gait phases and in the percentage of the gait cycle at which maximum plantar flexion of the ankle occurred in gait. The neuro-muscular and musculo-skeletal characteristics of children with joint hypermobility are different from those of non-hypermobile children. The Beighton, Solomon and Soskolne (1973) screening criteria successfully classified joint hypermobility in children. As a result of this study joint hypermobility has been identified as a variable which must be controlled in studies of foot morphology and function in children. The outcomes of this study provide a basis upon which to further explore the association between joint hypermobility and neuro-muscular and musculo-skeletal conditions, and, have relevance for the physical education of children with joint hypermobility, for footwear and orthotic design processes, and, in particular, for clinical identification and treatment of children with joint hypermobility.

L’instabilité chronique de la cheville (CAI) est un fardeau socioéconomique important qui entraine des répercussions néfastes chez la population atteinte, comme des récidives d’entorses de la cheville (ELC), qui peuvent notamment s’expliquer par des déficits biomécaniques aux membres inférieurs. Ces déficits sont notamment observés lors d’activités quotidiennes comme la marche, mais aussi lors de tâches plus difficiles comme l’atterrissage d’un saut. Par contre, les impacts biomécaniques réels d’une CAI lors de la locomotion ne sont pas encore clairement décrits. Les orthèses plantaires sont couramment utilisées dans le traitement de pathologies musculosquelettiques pour modifier les variables biomécaniques des membres inférieurs (cinématique, cinétique et électromyographie) responsables de ces pathologies. Bien que leurs effets sur la biomécanique du membre inférieur d’individus atteints d’une CAI soient encore méconnus, les orthèses plantaires pourraient permettre de les traiter plus efficacement. Les objectifs principaux de cette thèse étaient de déterminer les déficits biomécaniques associés à la CAI lors de la locomotion et lesquels de ces déficits peuvent être atténués avec le port d’orthèses plantaires. L’Étude 1 consistait à réaliser une revue systématique de la littérature sur les impacts biomécaniques d’une CAI lors d’une tâche de marche et de course. L’Étude 2 consistait à identifier les différences biomécaniques entre des individus avec et sans CAI à la marche. L’Étude 3 consistait à déterminer les différences biomécaniques entre des individus avec et sans CAI lors de l’atterrissage d’un saut unipodal sur une surface plane (DROP), inclinée (WEDGE) et instable (FOAM) ainsi qu’à l’atterrissage d’un saut latéral maximal unipodal (SIDE). Finalement, l’Étude 4 consistait à déterminer les effets des orthèses plantaires sur la biomécanique du membre inférieur d’individus atteints d’une CAI lors des tâches de marche et d’atterrissage d’un saut unipodal. À la marche, les individus atteints d’une CAI présentent de nombreux déficits biomécaniques qui pourraient les prédisposer à subir d’autres ELC, notamment une augmentation de l’inversion et de la flexion plantaire de la cheville. Ces augmentations de mouvement à la cheville contribuent à augmenter les forces verticales latérales au pied, à modifier la cinématique et la cinétique du genou ainsi que l’activité des muscles moyen fessier et long fibulaire. Lors de l’atterrissage d’un saut unipodal, les individus atteints d’une CAI présentent une augmentation de la dorsiflexion de la cheville afin de stabiliser l’articulation. Lors de la tâche WEDGE, la diminution de la préactivation musculaire du long fibulaire pourrait mettre ces individus plus à risque de subir d’autres ELC. De plus, le port d’orthèses plantaires diminue l’activité musculaire du tibial antérieur lors de la tâche DROP et du biceps fémoral à la marche chez des individus atteints d’une CAI. Elles semblent n’avoir aucun effet significatif sur la cinématique et cinétique du membre inférieur lors de la marche et l’atterrissage d’un saut unipodal. Finalement, cette thèse permet de mieux identifier les déficits biomécaniques à adresser lors de l’élaboration de plan de traitement pour les individus atteints d’une CAI et de mieux comprendre les effets des orthèses plantaires pour atténuer ces déficits. / Chronic ankle instability (CAI) is a major socioeconomic burden and has adverse repercussions for the affected population, such as recurrence of lateral ankle sprains (LAS), which could be explained by lower limb biomechanical deficits. These deficits are observed during daily activities such as walking but also during more difficult tasks such as jump landing. However, the real impact of CAI during locomotion has not yet been clearly described. Foot orthoses are commonly used to treat musculoskeletal pathologies because they modify lower limb biomechanics (kinematics, kinetics and electromyography). However, their effects on lower limb’s biomechanics of individuals with CAI are still unknown. Foot orthoses may help to treat the individuals with CAI more effectively. The main objectives of this thesis were to determine the biomechanical deficits associated with CAI during locomotion and which of these deficits can be attenuated with foot orthoses. Study 1 consisted of systematically reviewing the literature on the biomechanical deficits associated with CAI during walking and running. Study 2 consisted of identifying the biomechanical differences between individuals with and without CAI during walking. Study 3 consisted of determining the biomechanical differences between individuals with and without CAI during unilateral jump landing on even (DROP), inclined (WEDGE) and unstable (FOAM) surfaces and during a unilateral maximal side jump landing (SIDE). Study 4 consisted of determining the effects of foot orthoses on lower limb’s biomechanics of individuals with CAI during walking and unilateral jump landing. During walking, individuals with CAI present many biomechanical deficits that may predispose them to sustain recurrent LAS, including increased ankle inversion and plantarflexion. These contribute to increase the lateral vertical forces under the foot, to modify knee kinematics and kinetics as well as the activity of the gluteus medius and peroneus longus muscles. During unilateral jump landing, individuals with CAI present increased ankle dorsiflexion in order to stabilize the joint. During the WEDGE task, the decreased peroneus longus muscle preactivation could put these individuals at greater risk of sustaining recurrent LAS. In addition, wearing foot orthoses decreases the muscular activity of the tibialis anterior during the DROP task and the biceps femoris during walking in individuals with CAI. FOs have no significant effect on the kinematics and kinetics of the lower limb during walking and unilateral jump landing. Finally, the results of this thesis will help to better identify the biomechanical deficits to be addressed during rehabilitation for individuals with CAI and to better understand the effects of foot orthoses to attenuate these deficits.