INTRODUÇÃO: Anualmente nos E.U. A, estima-se mais de 250.000 mil casos de lesão do ligamento cruzado anterior, o que torna a reconstrução cirúrgica um procedimento comum na pratica da medicina esportiva. Ainda não existe consenso sobre o quanto de atividade promove uma reabilitação adequada sem prejudicar o enxerto ou produzir uma frouxidão anterior anormal, com consequente dano ao menisco e a cartilagem articular. OBJETIVO: Analisar e comparar o efeito de um protocolo de fisioterapia acelerado na estabilidade anterior e evolução clínica dos indivíduos submetidos à reconstrução do ligamento cruzado anterior. MÉTODOS: Foram incluídos 29 indivíduos no estudo que apresentaram ruptura total do LCA confirmada por RM e submetidos à reconstrução ligamentar com Tendão patelar. Aleatoriamente foram alocados em dois grupos com intervalos de reabilitação diferentes: Grupo Acelerado (4 meses) ou Grupo Convencional (6 meses). No pré-operatório, sexto e no quarto mês de pós-operatório um avaliador cego registrou: a lassidão anterior através do KT1000, Força muscular (CYBEX) e a função do joelho acometido através do IKDC (2000) e o Hop Test. RESULTADOS: os grupos foram semelhantes em relação aos dados demográficos. Não foi encontrada diferença estatística na lassidão anterior no quarto mês 0,92mm versus 1,33mm e no sexto mês 0,50mm versus 1,67mm sendo Grupo Convencional versus Grupo Acelerado respectivamente. No quarto mês o Grupo Acelerado apresentou uma melhora significativa (P< 0,001) na evolução clínica do IKDC (2000) 79,50 versus 60,61 do Grupo Convencional, essa diferença não se repetiu no sexto mês. A força muscular e o Hop Test, o Grupo Acelerado apresentou maiores valores, mas não de forma significativa nos dois momentos de avaliação (P> 0.05). CONCLUSÃO: Com base nos resultados obtidos, o protocolo acelerado quando comparado ao Convencional, não se diferiu quanto à estabilidade anterior do joelho e foi suficiente para demonstrar uma melhora significativa precoce na evolução clínica do joelho / BACKGROUND: Each year in the US, it is estimated more than 250 million cases of anterior cruciate ligament injury, which makes surgical reconstruction a common procedure in the practice of sports medicine. There is still no consensus on how much activity to promote adequate rehabilitation without damaging the graft or produce an abnormal anterior laxity, with consequent damage to the meniscus and articular cartilage. PURPOSE: To analyze and compare the effect of an accelerated physiotherapy protocol in the anterior-stability and clinical outcome of patients undergoing reconstruction of the anterior cruciate ligament. METHODS: We included 29 subjects in the study who had total ACL rupture confirmed by MRI and underwent ligament reconstruction with patellar tendon. Patients were randomly allocated in two groups with different rehabilitation intervals: Accelerated Group (4 months) or Conventional Group (6 months). Preoperatively, six and four months postoperatively a blind evaluator recorded: anterior laxity by KT1000, Brawn (CYBEX) and knee function affected by IKDC (2000) and the Hop Test. RESULTS: the groups were similar relative to demographic data. There was no statistical difference in anterior laxity in the fourth month 0,92mm versus 1.33mm and 0.50mm in the sixth month versus 1,67mm being conventional group versus accelerated group respectively. In the fourth month the accelerated group showed a significant improvement (P <0.001) in the clinical evolution of the IKDC (2000) 79.50 versus 60.61 in the conventional group, this difference was not repeated in the sixth month. Muscle strength and the Hop Test, the fast group had higher values, but not significantly in both time points (P> 0.05). CONCLUSION: Based on these results, the Accelerated protocol when compared to conventional, do not differ as the anterior knee stability and was sufficient to establish an early significant improvement in the clinical outcome of the knee

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

INTRODUÇÃO: Anualmente nos E.U. A, estima-se mais de 250.000 mil casos de lesão do ligamento cruzado anterior, o que torna a reconstrução cirúrgica um procedimento comum na pratica da medicina esportiva. Ainda não existe consenso sobre o quanto de atividade promove uma reabilitação adequada sem prejudicar o enxerto ou produzir uma frouxidão anterior anormal, com consequente dano ao menisco e a cartilagem articular. OBJETIVO: Analisar e comparar o efeito de um protocolo de fisioterapia acelerado na estabilidade anterior e evolução clínica dos indivíduos submetidos à reconstrução do ligamento cruzado anterior. MÉTODOS: Foram incluídos 29 indivíduos no estudo que apresentaram ruptura total do LCA confirmada por RM e submetidos à reconstrução ligamentar com Tendão patelar. Aleatoriamente foram alocados em dois grupos com intervalos de reabilitação diferentes: Grupo Acelerado (4 meses) ou Grupo Convencional (6 meses). No pré-operatório, sexto e no quarto mês de pós-operatório um avaliador cego registrou: a lassidão anterior através do KT1000, Força muscular (CYBEX) e a função do joelho acometido através do IKDC (2000) e o Hop Test. RESULTADOS: os grupos foram semelhantes em relação aos dados demográficos. Não foi encontrada diferença estatística na lassidão anterior no quarto mês 0,92mm versus 1,33mm e no sexto mês 0,50mm versus 1,67mm sendo Grupo Convencional versus Grupo Acelerado respectivamente. No quarto mês o Grupo Acelerado apresentou uma melhora significativa (P< 0,001) na evolução clínica do IKDC (2000) 79,50 versus 60,61 do Grupo Convencional, essa diferença não se repetiu no sexto mês. A força muscular e o Hop Test, o Grupo Acelerado apresentou maiores valores, mas não de forma significativa nos dois momentos de avaliação (P> 0.05). CONCLUSÃO: Com base nos resultados obtidos, o protocolo acelerado quando comparado ao Convencional, não se diferiu quanto à estabilidade anterior do joelho e foi suficiente para demonstrar uma melhora significativa precoce na evolução clínica do joelho / BACKGROUND: Each year in the US, it is estimated more than 250 million cases of anterior cruciate ligament injury, which makes surgical reconstruction a common procedure in the practice of sports medicine. There is still no consensus on how much activity to promote adequate rehabilitation without damaging the graft or produce an abnormal anterior laxity, with consequent damage to the meniscus and articular cartilage. PURPOSE: To analyze and compare the effect of an accelerated physiotherapy protocol in the anterior-stability and clinical outcome of patients undergoing reconstruction of the anterior cruciate ligament. METHODS: We included 29 subjects in the study who had total ACL rupture confirmed by MRI and underwent ligament reconstruction with patellar tendon. Patients were randomly allocated in two groups with different rehabilitation intervals: Accelerated Group (4 months) or Conventional Group (6 months). Preoperatively, six and four months postoperatively a blind evaluator recorded: anterior laxity by KT1000, Brawn (CYBEX) and knee function affected by IKDC (2000) and the Hop Test. RESULTS: the groups were similar relative to demographic data. There was no statistical difference in anterior laxity in the fourth month 0,92mm versus 1.33mm and 0.50mm in the sixth month versus 1,67mm being conventional group versus accelerated group respectively. In the fourth month the accelerated group showed a significant improvement (P <0.001) in the clinical evolution of the IKDC (2000) 79.50 versus 60.61 in the conventional group, this difference was not repeated in the sixth month. Muscle strength and the Hop Test, the fast group had higher values, but not significantly in both time points (P> 0.05). CONCLUSION: Based on these results, the Accelerated protocol when compared to conventional, do not differ as the anterior knee stability and was sufficient to establish an early significant improvement in the clinical outcome of the knee

No description available.

Objective: The primary aim of this research was to examine the temporal pattern of neuromuscular quadriceps deficits in both the involved and uninvolved limbs of patients assigned to the control group after anterior cruciate ligament reconstruction (ACLr), by assessing quadriceps strength, voluntary activation, and corticomotor excitability prior to surgery (baseline), three months after ACLr, and six months after ACLr. A secondary aim of this research was to determine whether quadriceps strength, voluntary activation, and/or corticomotor excitability assessed in patients prior to ACLr and/or at three months after surgery, is predictive of lower extremity postural control and/or self-reported function at six months after ACLr. Lastly, a tertiary aim of this research was to determine if a 12-week home-based neuromuscular electrical stimulation (Home-NMES) program elicits greater bilateral improvements in quadriceps strength, voluntary activation, and corticomotor excitability of patients at three and six months after ACLr compared to a 12-week standard home-exercise program (control group). Participants: Fifty patients scheduled to undergo unilateral ACLr were randomly allocated to the home-NMES group (19 Female, 6 Male; age: 18.9 ± 5.4 years; height: 170.8 ± 9.7 cm; weight: 74.6 ± 18.5 kg; 28.0±20.0 days-post-injury) or control group (14 Female, 11 Male; age: 19.4 ± 4.5 years; height: 171.1 ± 11.5 cm; weight: 70.7 ± 11.9 kg). Methods: A randomized clinical trial design was used in this study. Prior to ACLr, isometric quadriceps strength and voluntary quadriceps activation were assessed in both limbs of patients, and corticomotor excitability was assessed in the involved limb. Three days after ACLr, both groups were instructed to begin their allocated interventions. The Home-NMES group administered NMES to their involved limb’s quadriceps three sessions a day for 15 minutes, and five days a week for 12 weeks using a portable NMES device. The control group was treated according to the current standard-of-care, but they were also instructed to perform volitional isometric quadriceps contractions for the same duration and frequency as the Home-Based NMES protocol. The outcomes measures were reassessed in both groups at three and six months post-ACLr. Main Outcome Measures: Quadriceps strength and voluntary activation were assessed using maximal voluntary isometric contractions and the superimposed burst technique, respectively. Normalized peak knee extension torque and central activation ratio were used to quantify isometric quadriceps strength and activation, respectively. Corticomotor excitability was evaluated with transcranial magnetic stimulation, and quantified with active motor threshold). The Y-balance test anterior reach (YBT-A) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used to assess the patients lower extremity knee function at six months post-ACLr. Statistical Analyses: Specific Aim 1: A 2x3 (limb x time) mixed model, ANOVA with repeated measures was performed in the control group to assess differences between the involved limb and the uninvolved limb for isometric quadriceps strength, and voluntary quadriceps activation over time. A one-way mixed model, ANOVA with repeated measures was performed in the control group to assess differences in corticomotor excitability over time. Post-hoc comparisons were performed when appropriate. Specific Aim 2: Separate, mixed model, linear regression analyses were performed in the control group (involved limb) to determine the effect that the neuromuscular quadriceps outcome measures assessed at baseline and 3 months post-ACLr, had on lower extremity knee functional outcome measures assessed at 6 months post-ACLr. Specific Aim 3: A 2x2x3 (group x limb x time) mixed model, ANOVA with repeated measures was performed to assess group differences between the involved limb and the uninvolved limb in isometric quadriceps strength, and voluntary quadriceps activation over time. A 2x3 (group x time) mixed model, ANOVA with repeated measures was performed to assess group differences in corticomotor excitability over time. Post-hoc comparisons were performed when appropriate. Results: Aim 1: Patients demonstrated lower quadriceps strength on their involved limb compared to their uninvolved limb at baseline, three months post-ACLr, and six months post-ACLr. Quadriceps strength progressively decreased in the involved limb of patients from baseline to 3 months post-ACLr, baseline to 6 months post-ACLr, and increased from 3 months to 6 months post-ACLr. Quadriceps strength was also decreased in the uninvolved limb of patients from baseline to 6 months post-ACLr. ). Irrespective of when it was assessed, voluntary quadriceps activation was higher in the involved limb of patients compared to their uninvolved limb. There were no changes in corticomotor excitability of the involved limb over time. Specific Aim 2: The quadriceps strength of patients at three months post-ACLr had a significant positive effect on their 6-month YBT-A performance KOOS score. ). Neither voluntary quadriceps activation or corticomotor excitability or AMT (at baseline or 3-month post-ACLr) had a significant effect on any of the 6-month lower extremity functional outcome measures. Specific Aim 3: Irrespective of limb or when it was assessed, quadriceps strength was higher in the control group compared to the Home-NMES group. Both groups demonstrated lower quadriceps strength on their involved limbs compared to their uninvolved limbs at baseline, three months post-ACLr, and six months post-ACLr. Quadriceps progressively decreased in the involved limbs of both groups from baseline to three months post-ACLr and baseline to six months post-ACLr, and increased from three months to six months post- ACLr. At baseline, voluntary quadriceps activation was higher in the involved limbs of both groups compared to their uninvolved limbs. There were no group differences or changes over time observed in the involved limb of both groups with corticomotor excitability. Conclusion: Although quadriceps weakness is more apparent in the involved limb of patients after ACLr, the quadriceps strength of their uninvolved limb was also affected. Clinicians are encouraged to not rely on a quadriceps strength limb symmetry index when making return-sport-decisions for their patients after recovering from ACLr. The quadriceps in the uninvolved limb of patients demonstrated more inhibition, which may explain the quadriceps strength deficits observed in the uninvolved limb of patients following ACLr. To reduce the risk of subsequent injury upon return-to-sport and protect against the development of knee OA, we recommend that clinicians incorporate bilateral interventions aimed at restoring quadriceps strength and disinhibiting the quadriceps. Intensive quadriceps strengthening should be performed in the early stages of ACLr rehabilitation, so that lower extremity function can be improved in patients later on. Lastly, the effectiveness of home-based NMES as a modality for restoring quadriceps strength and activation in patients after ACLr is inconclusive. Home-based NMES provides patients with the ability to receive higher doses of NMES to the quadriceps; but its effectiveness may be limited by low contraction intensities and poor treatment compliance in patients.

Thesis (MScPhysio)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The anterior cruciate ligament is the most commonly injured ligament in the knee, with only one third of athletes returning to their pre-injury level of sport. Identifying intrinsic factors associated with an increased likelihood of return to sport may improve the surgical outcome. A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. The objective was to systematically appraise publications describing intrinsic factors which may be associated with return to sport, after anterior cruciate ligament reconstruction. A comprehensive eligibility checklist was composed. Methodological quality appraisal of cohort studies revealed that high quality studies were included in the review. A descriptive synthesis of the findings associating intrinsic factors with return to sport was performed. Ten studies were included. The most important finding was the association of fear of re-injury preventing return to sports participation. Knee function did not always correspond with the likelihood of returning to sport. Younger athletes and competitive, male athletes appeared more likely to return. Across these studies, the 141 athletes not returning to pre-injury sport were questioned as to the reason for non return. An average of 35% (49 athletes) cited fear of re-injury as the reason. Fear of re-injury was thus investigated further as it could be considered in the post-operative management of anterior cruciate ligament reconstruction. In a qualitative study with supplemental cross-sectional analysis, factors informing fear of re-injury were explored. Male and female athletes, aged 17-50 years were included (n=59). Reconstruction procedures using any graft type were included; however revision and multi-ligament reconstruction was excluded. Twenty-four participants (41%) did not return to the pre-injury sport. Those citing fear of re-injury as the only reason for not-retuning to sport were interviewed (n=12). Thus, those who did not return to pre-injury type and level of sport despite good knee function. Athletes’ experiences informing fear of re-injury were explored by semi-structured interviews. Data analysis was performed by content analysis. Codes were allocated and categorised and these categories were synthesised into themes. The Qualitative review guidelines – RATS were followed. From the participant interviews, four themes emerged: undergoing the surgery and recovery again, nature of the pre-injury sport imposing risk of re-injury, personality traits, and social priorities. An accelerated rehabilitation programme was suggested to improve the post–operative experience. The supplementary analysis revealed athletes younger than 20 years of age were more likely to return to sport. Modifiable fears include pain, length of rehabilitation, mechanism of injury and psychological aspects. Pain management, motivation and education are important considerations post-operatively and during rehabilitation. Clinicians should be aware of factors informing fear of re-injury on an individual basis to develop a tailored management plan. / AFRIKAANSE OPSOMMING: OPSOMMING Die anterior kruisligament is die mees algemeen beseerde ligamente in die knie, met slegs een derde van die atlete wat terugkeer na hul pre-besering vlak van sport. Identifisering van intrinsieke faktore wat verband hou met 'n verhoogde moontlikheid van terugkeer na sport kan die chirurgiese uitkoms verbeter. 'n Sistematiese oorsig wat die Voorkeur Verslag Items vir Sistematiese oorsig en Meta-ontledingsriglyne volg, is uitgevoer . Die doel was om stelselmatig publikasies, wat intrinsieke faktore beskryf wat verband hou met terugkeer na sport na anterior kruisligament rekonstruksie, te beoordeel. 'n Omvattende kontrolelys is saamgestel. Metodologiese kwaliteit beoordeling van ‘n groep studies het 'n hoë gehalte studie aan die lig gebring, wat ingesluit is in die oorsig. 'n Beskrywende sintese van die bevindinge wat intrinsieke faktore met die terugkeer na sport assosieer, is uitgevoer. Tien studies is ingesluit. Die belangrikste bevinding wat terugkeer na sportdeelname verhinder was die vrees van herbesering. Kniefunksie het nie altyd ooreengestem met die moontlikheid van terugkeer na sport nie. Jonger atlete en wedywerende manlike atlete was meer geneig om terug te keer. In al die ingesluite studies, is die 141 atlete wat nie teruggekeer het na sport voorbesering ondervra oor die rede vir nie terugkeer. 'n Gemiddeld van 35% (49 atlete) het vrees vir herbesering as rede aangevoer. Vrees vir herbesering is dus verder ondersoek, as oorwegende faktor in die post-operatiewe bestuur van anterior kruisligament rekonstruksie. In 'n primêre, kwalitatiewe studie met aanvullende deursnee-analise, is die redes vir die vrees vir herbesering ondersoek. Manlike en vroulike atlete, tussen die ouderdomme van 17-50 jaar is ingesluit (n = 59). Rekonstruksie prosedures deur enige soort oorplanting is ingesluit; hersiening en verskeie ligament rekonstruksie is egter uitgesluit. Vier-en-twintig deelnemers (41%) het nie teruggekeer na die pre-besering sport nie. Diegene wat vrees vir herbesering as die enigste rede vir nie terugkering na sport aanvoer, is onderhoude mee gevoer (n = 12). Dus, diegene wat nie teruggekeer het na pre-besering, tipe en vlak, van sport ten spyte van goeie knie funksie. Die redes vir die vrees vir herbesering is ondersoek deur semi-gestruktureerde onderhoude. Dataanalise is uitgevoer deur die inhoud / tematiese analise. Kodes is toegeken en gekategoreer. Hierdie kategorieë is herverdeel in temas. Uit die deelnemer onderhoude, het vier temas na vore gekom: die operasie en herstel proses, die aard van die prebesering sport as risiko vir herbesering, persoonlikheidseienskappe en sosiale prioriteite. 'n Versnelde rehabilitasieprogram is voorgestel om die post-operatiewe ervaring te verbeter. Die aanvullende analise het getoon dat atlete jonger as 20 jaar oud meer geneig was om terug te keer na die sport. Aanpasbare oorsake van vrees sluit in pyn, die lengte van rehabilitasie, meganisme van besering en sielkundige aspekte. Pyn bestuur, motivering en opvoeding is belangrike oorwegings post-operatief en tydens rehabilitasie. Dokters en fisioterapeute moet bewus wees van die vrees vir herbesering en die veranderbare oorsake daarvan ondersoek op 'n individuele basis om 'n pasient spesifieke bestuursplan te ontwikkel.

Thesis (MScPhysio)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Introduction ACL injuries are among the most serious injuries that professional and amateur sports men and women sustain. More than 120 000 ACL injuries occur annually in the USA alone. The highest incidence of ACL injuries are seen in multi-directional and multi-factorial sports such as soccer, basketball, lacrosse, American football, rugby and Australian rules football. It is hoped that the proposed review will clarify issues relating to the effect of fatigue on knee control, as it will focus on multiple movements found in different sporting codes. By including both studies on healthy adults as well as subjects who have sustained ACL injuries, a clearer picture can be formed on the global effect of fatigue on knee control. Objective The objective of this review was to identify, collate and analyse the current evidence on the effect of fatigue protocols on knee control during functional tasks, such as side-stepping, bilateral jumping/landing and crossover-cutting. Methodology A comprehensive search of electronic databases was conducted between April 2013 and August 2013 (updated in April 2014) for eligible articles for inclusion in the review. Methodological quality was assessed using a modified Downs and Black checklist. Results Ten studies met the eligibility criteria and were included in the review. The included studies reported a wide variety of fatigue protocols. Several different test movements were utilised in the studies. The test movements included cutting movements, drop jumps, stop jumps, vertical jumps, bilateral drop landing and rotational movements. The overall results indicated that fatigue had a negative impact on knee control. There were however studies which reported conflicting results. Gender differences were also highlighted in the results of included studies where it became evident that females tend to be more susceptible to knee injuries due to altered kinematics as a result of fatigue. Conclusion Fatigue generally seems to affect knee control negatively across various fatigue protocols. Future research should investigate using a standardised fatigue protocol to achieve more accurate and consistent results during the different functional activities. / AFRIKAANSE OPSOMMING: Nie beskikbaar

Anterior cruciate ligament injury leads to increased sagittal tibial translation, and perceptions of instability and low confidence in the knee joint are common. Many patients have remaining problems despite treatment and are forced to lower their activity level and prematurely end their career in sports. The effect of ACL reconstruction and/or rehabilitation on dynamic knee stability is not completely understood. The overall aim of this thesis was to study the dynamic knee stability during and after rehabilitation in individuals with ACL injury. More specific aims were 1) to elaborate an evaluation method for muscle strength, 2) to evaluate the effect of exercises in closed and open kinetic chain, and 3) to evaluate dynamic knee stability in patients with ACL deficiency or ACL reconstruction. Sagittal tibial translation and knee flexion angle were measured using the CA‐4000 computerised goniometer linkage. Muscle activation was registered with electromyography. The intra‐ and inter‐rater reliability of 1 repetition maximum (RM) of seated knee extension was clinically acceptable. The inter‐rater reliability of 1RM of squat was also acceptable, but the intra‐rater reliability was lower. The systematic procedure for the establishment of 1RM that was developed can be recommended for use in the clinic. One specific exercise session including cycling and a maximum number of knee extensions and heel raises did not influence static or dynamic sagittal tibial translation in uninjured individuals. A comprehensive rehabilitation program with isolated quadriceps training in OKC led to significantly greater isokinetic quadriceps strength compared to CKC rehabilitation in patients with ACL deficiency. Hamstring strength, static and dynamic translation, and functional outcome were similar between groups. Five weeks after ACL reconstruction, seated knee extension produced more anterior tibial translation compared to the straight leg raise and standing on one leg. All exercises produced less or equal amount of anterior tibial translation as the 90N Lachman test. Five weeks after the ACL reconstruction the static and dynamic tibial translation in the ACL reconstructed knee did not differ from the tibial translation on the uninjured leg. Patients in the early phase after ACL injury or ACL reconstruction used a joint stiffening strategy including a reduced peak knee extension angle during gait and increased hamstring activation during activity, which reduces the dynamic tibial translation. Patients with ACL deficiency that completed a four months rehabilitation program used a movement pattern that was more close to normal.

Females suffer anterior cruciate ligament (ACL) injuries at a 2 to 10-fold greater rate compared to male athletes participating in similar sports. Altered movement patterns and inadequate knee stiffness are two interrelated factors that may increase ACL injury risk. Onset of these neuromuscular risk factors may coincide with the rapid adolescent growth that results in the divergence of a multitude of neuromuscular parameters between sexes. The overall purpose of this dissertation was to determine if neuromuscular ACL injury risk factors in female athletes increase following rapid growth and development compared to males. Male and female athletes were tested with three-dimensional motion analysis techniques during a drop vertical jump over two consecutive years to determine if ACL injury risk factors increased. Pubertal females showed a significant longitudinal increase in knee abduction angle compared to post-pubertal females and both male groups. The increase in knee abduction angle appeared to remain consistent, as the post pubertal female cohort had greater overall knee abduction compared to post-pubertal males. Similar results were found with a greater magnitude of knee abduction moment in post-pubertal females compared to males. Males and females increased ankle, knee and hip active stiffness from the first to second year of testing. Ankle and hip stiffness were increased significantly more in the pubertal group compared to post-pubertal. Sex and maturational group differences were found in hip and ankle joint stiffness. Post-pubertal males had significantly greater hip stiffness than the other groups (even when normalized to body mass). This indicates that post-pubertal males utilized a different neuromuscular strategy during landing. Males had a significantly greater increase from year to year in vertical jump height compared to females. Vertical jump height is often related to a measure of whole body power and indicates that males had a significant neuromuscular spurt compared to females. Early puberty appears to be a critical phase related to the divergence of increased ACL injury risk factors. Injury prevention programs that focus on neuromuscular training may be beneficial to help address the development of ACL injury risk factors that occur in female athletes during maturation.

Muscle strength capabilities are a determinant in the ability to successfully accomplish everyday tasks. As such, the quantification of this aspect of human performance is of interest in many settings. Currently, the validity of muscle strength test results is reliant on the notion that during testing, the participant exerted an effort that is sincere, and that consisted of maximal voluntary contractions. Therefore, the ability to differentiate between maximal and non maximal muscular exertions is of importance. The purpose of this dissertation was to develop and validate probability-based decision rules for differentiating between maximal and non-maximal voluntary exertions of the knee and shoulder joint musculature during isokinetic dynamometry-based testing. For development of the decision rules, healthy participants performed a series of maximal and non-maximal exertions at different testing velocities through a prescribed range of motion. Two different theory-based approaches were subsequently used for decision rule development: the first approach was based on expected better consistency in strength waveform shapes and relative magnitudes during performance of maximal efforts in comparison to non-maximal efforts. The second approach was based on the known force-velocity dependency in skeletal muscles. In terms of discriminatory performance, several of the decision rules pertaining to the knee joint markedly improve upon those previously reported. In addition, a separate investigation demonstrated that the decision rules offer excellent discriminatory performance when applied to test results of participants that have undergone surgical reconstruction of their anterior cruciate ligament. As such, clinicians and researchers may be able to ascertain voluntary maximal effort production during isokinetic testing of the knee joint musculature with a high degree of confidence, and thus be able to rely on such scores for decision-making purposes With regards to the shoulder musculature decision rules, several methodological issues related to test positioning and signal processing need to be addressed prior to consideration of their use in the clinical domain. / Thesis (Ph.D, Kinesiology & Health Studies) -- Queen's University, 2013-06-19 01:12:53.454