The objective of this study was to investigate the accuracy of eleven prediction equations and one prediction table when estimating isoinertial knee extension and leg press one repetition maximum (1-RM) performance in subjects with knee injuries and knee osteoarthritis. Study Design: A descriptive quantitative research study was undertaken utilizing a cross-sectional design. Background: Traumatic injuries and osteoarthritis are common musculoskeletal pathologies that can disrupt normal function of the knee joint. A frequent sequela of these pathologies is quadriceps femoris muscle weakness. Such weakness can contribute to disability and diminished levels of functional and recreational activity. Therefore, safe and accurate methods of measuring maximal strength are required to identify and quantify quadriceps strength deficits. One option proposed in the literature is the use of 1-RM prediction equations which estimate 1-RM performance from the number of repetitions completed with sub-maximal loads. These equations have been investigated previously using healthy populations and subjects with calf muscle injuries. However, to date, no known study has investigated their accuracy in individuals with joint pathologies. Method: Machine-weight seated knee extension and seated leg press exercises were investigated in this study. Twenty subjects with knee injuries and 12 subjects with knee OA completed the testing procedures for the knee extension exercise. Nineteen subjects with knee injuries and 18 subjects with knee OA completed the testing procedures for the leg press exercise. All subjects attended the testing venue on three occasions. At the first visit a familiarization session was carried out. At the second and third visits each subject was randomly assigned to perform either actual or predicted 1-RM testing for both of the exercises. Twelve different prediction methods were used to estimate 1-RM performance from the results. The estimates of 1-RM strength were then compared to actual 1-RM performance to assess the level of conformity between these measures. Statistical procedures including Bland and Altman analyses, intraclass correlation coefficients, typical error and total error of measurement were used in the analyses of the results. In addition, paired t-tests were performed to determine whether actual 1-RM values were significantly different across the control and affected limbs and whether there were any significant differences in predictive accuracy for each equation across the control and affected limbs. Finally, the number of subjects with predicted 1-RM values within 5% or less of their actual 1-RM values was determined for each equation. Results: When the knee injury group performed the knee extension exercise, the Brown, Brzycki, Epley, Lander, Mayhew et al., Poliquin and Wathen prediction methods demonstrated the greatest levels of predictive accuracy. When two atypical subjects were identified and excluded from the analyses, the accuracy of these equations improved further. Following the removal of these two subjects, no significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). Typical errors and total errors were low for the more accurate prediction methods ranging from 2.4-2.8% and from 2.4-3.5%, respectively. Overall, the Poliquin table appeared to be the most accurate prediction method for this sample (affected limbs: bias 0.3 kg, 95% limits of agreement (LOA) -5.8 to 6.4 kg, typical error as a coefficient of variation (COV) 2.4%, total error of measurement (total error) 2.4%; control limbs: bias -1.3 kg, 95% LOA -9.0 to 6.3 kg, typical error as a COV 2.7%, total error 2.8%). When the knee OA group performed the knee extension exercise, the Brown, Brzycki, Epley, Lander, Mayhew et al., Poliquin and Wathen prediction methods demonstrated the greatest levels of predictive accuracy. No significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). When an atypical subject was identified and excluded from the analyses, the accuracy of the equations improved further. Typical errors as COVs and total errors for the more accurate prediction methods ranged from 2.5-2.7% and from 2.4-2.9%, respectively. Overall, the Poliquin table appeared to be the most accurate prediction method for this sample (affected limbs: bias 0.9 kg, 95% LOA -4.5 to 6.3 kg, typical error as a COV 2.5%, total error 2.5%; control limbs: bias -0.1 kg, 95% LOA -6.0 to 5.9 kg, typical error as a COV 2.5%, total error 2.4%). When the knee injury group performed the leg press, the Adams, Berger, Lombardi and O’Connor equations demonstrated the greatest levels of predictive accuracy. No significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). Typical errors as COVs and total errors for the more accurate equations ranged from 2.8-3.2% and from 2.9-3.3%, respectively. Overall, the Berger (affected limbs: bias -0.4 kg, 95% LOA -7.2 to 6.3 kg, typical error as a COV 3.2%, total error 3.2%; control limbs: bias 0.1 kg, 95% LOA -6.6 to 6.7 kg, typical error as a COV 3.1%, total error 3.0%) and O’Connor equations (affected limbs: bias -0.6 kg, 95% LOA-6.8 to 5.7 kg, typical error as a COV 2.9%, total error 3.0%; control limbs: bias -0.2 kg, 95% LOA -6.9 to 6.4 kg, typical error as a COV 2.9%, total error 2.9%) appeared to be the most accurate prediction methods for this sample. When the knee OA group performed the leg press, the Adams, Berger, KLW, Lombardi and O’Connor equations demonstrated the greatest levels of predictive accuracy. No significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). The typical errors as COVs and the total error values for the more accurate prediction methods were the highest observed in this study, ranging from 5.8-6.0% and from 5.7-6.2%, respectively. Overall, the Adams, Berger, KLW and O’Connor equations appeared to be the most accurate prediction methods for this sample. However, it is possible that the predicted leg press 1-RM values produced by the knee OA group might not have matched actual 1-RM values closely enough to be clinically acceptable for some purposes. Conclusion: The findings of the current study suggested that the Poliquin table produced the most accurate estimates of knee extension 1-RM performance for both the knee injury and knee OA groups. In contrast, the Berger and O’Connor equations produced the most accurate estimates of leg press 1-RM performance for the knee injury group, while the Adams, Berger, KLW and O’Connor equations produced the most accurate results for the knee OA group. However, the higher error values observed for the knee OA group suggested that predicted leg press 1-RM performance might not be accurate enough for some clinical purposes. Finally, it can be concluded that no single prediction equation was able to accurately estimate both knee extension and leg press 1-RM performance in subjects with knee injuries and knee OA.

Syftet med denna undersökning är att mäta och identifiera eventuella förändringar över tid, vad gäller arbetsmiljön och måluppfyllelsen, under implementeringen av Quadriceps-pedagogiken på Ekhammarskolan. Arbetsmiljö definieras i denna studie som mål vilka Quadricepspedagogiken vill uppnå. Med måluppfyllelse menas niornas meritvärden och andelen elever som når alla målen i nian. Studiens metod utgår från en kvantitativ longitudinell utvecklingsstudie genomförd som en survey-undersökning där resultaten tolkas med en ansats som lutar åt skoleffektivitetsforskning. Resultatet kvantifieras till ett antal positiva och negativa förändringar över tid. Mätningen av arbetsmiljön gjordes utifrån frågeställningar där man vill uppnå det arbetssätt som Quadricepspedagogiken förespråkar. Frågeställningarna i enkäterna gav svar som eventuellt kan indikera positiva och negativa förändringar i arbetsmiljön. Enkäterna genomfördes åren 2006-2009. Resultatet visar att av 22 frågeställningar som ställts upp i problemformuleringen upplevdes 12 som positiva förändringar, 3 som oförändrade och 7 som negativa. Det mest utmärkande var att eleverna upplevde att lektionernas startblock gav en lugnare och tystare ingång till och början på lektionen, att börja-med-uppgiften underlättade för dem att komma igång med lektionen och att koncentration under lektionerna blev bättre. Studien av måluppfyllelsen, det vill säga meritvärdena samt andelen elever som når målen, varierade kraftigt under åren 2006-2009. Variationen kan inte ha något samband med Quadricepspedagogikens införande. Det behövs ytterligare forskning för att kunna fastställa hur meritvärdena förändras över tid. Författaren föreslår i diskussionen yterliggare studier av flera skolor som infört Quadricepspedagogiken och hur deras meritvärden förändras över tid.

The objective of this study was to investigate the accuracy of eleven prediction equations and one prediction table when estimating isoinertial knee extension and leg press one repetition maximum (1-RM) performance in subjects with knee injuries and knee osteoarthritis. Study Design: A descriptive quantitative research study was undertaken utilizing a cross-sectional design. Background: Traumatic injuries and osteoarthritis are common musculoskeletal pathologies that can disrupt normal function of the knee joint. A frequent sequela of these pathologies is quadriceps femoris muscle weakness. Such weakness can contribute to disability and diminished levels of functional and recreational activity. Therefore, safe and accurate methods of measuring maximal strength are required to identify and quantify quadriceps strength deficits. One option proposed in the literature is the use of 1-RM prediction equations which estimate 1-RM performance from the number of repetitions completed with sub-maximal loads. These equations have been investigated previously using healthy populations and subjects with calf muscle injuries. However, to date, no known study has investigated their accuracy in individuals with joint pathologies. Method: Machine-weight seated knee extension and seated leg press exercises were investigated in this study. Twenty subjects with knee injuries and 12 subjects with knee OA completed the testing procedures for the knee extension exercise. Nineteen subjects with knee injuries and 18 subjects with knee OA completed the testing procedures for the leg press exercise. All subjects attended the testing venue on three occasions. At the first visit a familiarization session was carried out. At the second and third visits each subject was randomly assigned to perform either actual or predicted 1-RM testing for both of the exercises. Twelve different prediction methods were used to estimate 1-RM performance from the results. The estimates of 1-RM strength were then compared to actual 1-RM performance to assess the level of conformity between these measures. Statistical procedures including Bland and Altman analyses, intraclass correlation coefficients, typical error and total error of measurement were used in the analyses of the results. In addition, paired t-tests were performed to determine whether actual 1-RM values were significantly different across the control and affected limbs and whether there were any significant differences in predictive accuracy for each equation across the control and affected limbs. Finally, the number of subjects with predicted 1-RM values within 5% or less of their actual 1-RM values was determined for each equation. Results: When the knee injury group performed the knee extension exercise, the Brown, Brzycki, Epley, Lander, Mayhew et al., Poliquin and Wathen prediction methods demonstrated the greatest levels of predictive accuracy. When two atypical subjects were identified and excluded from the analyses, the accuracy of these equations improved further. Following the removal of these two subjects, no significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). Typical errors and total errors were low for the more accurate prediction methods ranging from 2.4-2.8% and from 2.4-3.5%, respectively. Overall, the Poliquin table appeared to be the most accurate prediction method for this sample (affected limbs: bias 0.3 kg, 95% limits of agreement (LOA) -5.8 to 6.4 kg, typical error as a coefficient of variation (COV) 2.4%, total error of measurement (total error) 2.4%; control limbs: bias -1.3 kg, 95% LOA -9.0 to 6.3 kg, typical error as a COV 2.7%, total error 2.8%). When the knee OA group performed the knee extension exercise, the Brown, Brzycki, Epley, Lander, Mayhew et al., Poliquin and Wathen prediction methods demonstrated the greatest levels of predictive accuracy. No significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). When an atypical subject was identified and excluded from the analyses, the accuracy of the equations improved further. Typical errors as COVs and total errors for the more accurate prediction methods ranged from 2.5-2.7% and from 2.4-2.9%, respectively. Overall, the Poliquin table appeared to be the most accurate prediction method for this sample (affected limbs: bias 0.9 kg, 95% LOA -4.5 to 6.3 kg, typical error as a COV 2.5%, total error 2.5%; control limbs: bias -0.1 kg, 95% LOA -6.0 to 5.9 kg, typical error as a COV 2.5%, total error 2.4%). When the knee injury group performed the leg press, the Adams, Berger, Lombardi and O’Connor equations demonstrated the greatest levels of predictive accuracy. No significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). Typical errors as COVs and total errors for the more accurate equations ranged from 2.8-3.2% and from 2.9-3.3%, respectively. Overall, the Berger (affected limbs: bias -0.4 kg, 95% LOA -7.2 to 6.3 kg, typical error as a COV 3.2%, total error 3.2%; control limbs: bias 0.1 kg, 95% LOA -6.6 to 6.7 kg, typical error as a COV 3.1%, total error 3.0%) and O’Connor equations (affected limbs: bias -0.6 kg, 95% LOA-6.8 to 5.7 kg, typical error as a COV 2.9%, total error 3.0%; control limbs: bias -0.2 kg, 95% LOA -6.9 to 6.4 kg, typical error as a COV 2.9%, total error 2.9%) appeared to be the most accurate prediction methods for this sample. When the knee OA group performed the leg press, the Adams, Berger, KLW, Lombardi and O’Connor equations demonstrated the greatest levels of predictive accuracy. No significant differences in predictive accuracy were found for any of the equations across the affected and control limbs (p > 0.05). The typical errors as COVs and the total error values for the more accurate prediction methods were the highest observed in this study, ranging from 5.8-6.0% and from 5.7-6.2%, respectively. Overall, the Adams, Berger, KLW and O’Connor equations appeared to be the most accurate prediction methods for this sample. However, it is possible that the predicted leg press 1-RM values produced by the knee OA group might not have matched actual 1-RM values closely enough to be clinically acceptable for some purposes. Conclusion: The findings of the current study suggested that the Poliquin table produced the most accurate estimates of knee extension 1-RM performance for both the knee injury and knee OA groups. In contrast, the Berger and O’Connor equations produced the most accurate estimates of leg press 1-RM performance for the knee injury group, while the Adams, Berger, KLW and O’Connor equations produced the most accurate results for the knee OA group. However, the higher error values observed for the knee OA group suggested that predicted leg press 1-RM performance might not be accurate enough for some clinical purposes. Finally, it can be concluded that no single prediction equation was able to accurately estimate both knee extension and leg press 1-RM performance in subjects with knee injuries and knee OA.

Diss. (sammanfattning) Umeå : Umeå universitet, 2005. / Härtill 4 uppsatser.

Thesis (M.S.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Made available in DSpace on 2014-12-17T15:37:05Z (GMT). No. of bitstreams: 1 JenifferCM_DISSERT.pdf: 926553 bytes, checksum: 802fba8946218d778ebe9345c0c66294 (MD5) Previous issue date: 2012-03-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In order to characterize the seasonal and daily rhythm of Dinoponera quadriceps foraging activity in natural environment, four colonies of D. quadriceps were observed in an area of secondary Atlantic forest in northeastern Brazil. Data collection was performed during 72 hours every three months during an annual cycle. Colonies of D. quadriceps exhibited seasonal variation in foraging activity, peaking in the early dry season, followed by a sudden decline at the end of this season and increasing again at the late rainy season. The seasonal rhythm of foraging was positively related to the duration of the daylight and luminosity, and negatively to the time of sunrise and rainfall. Regarding the daily rhythm, foraging activity was predominantly diurnal independent of season. At the early dry season, the colonies had two activity peaks, one in the morning and another in the afternoon, with a decrease in foraging at midday, while in the rest of the year foraging activity was distributed more evenly throughout the daylight. The daily rhythm of foraging activity had a stronger and positive relation with light intensity. The second most important factor determining the daily rhythm of foraging was temperature that was also positively related for most of the year. Relative humidity showed a weak and negative relation with the daily rhythm of foraging in just one month of observation / A fim de caracterizar o ritmo sazonal e di?rio da atividade de forrageio de Dinoponera quadriceps em ambiente natural, foram observadas quatro col?nias de D. quadriceps em ?rea de mata atl?ntica secund?ria no nordeste do Brasil. A coleta de dados foi realizada durante 72 horas ininterruptas a cada tr?s meses, durante um ciclo anual. As col?nias de D. quadriceps exibiram varia??o sazonal da atividade de forrageio, com pico no in?cio da esta??o seca, seguido por uma queda brusca no final dessa esta??o e tendendo a aumentar novamente no final da esta??o chuvosa. O ritmo sazonal de forrageio foi relacionado positivamente ? dura??o da fase clara e ? luminosidade, e negativamente ao hor?rio de nascer do sol e ? pluviosidade. Em rela??o ao ritmo di?rio, a atividade de forrageio foi predominantemente diurna independente da esta??o do ano. No in?cio da esta??o seca, as col?nias tiveram dois picos de atividade, um pela manh? e outro ? tarde, com diminui??o do forrageio no meio do dia, enquanto que no resto do ano a atividade de forrageio foi distribu?da de forma mais uniforme ao longo da fase clara. O ritmo di?rio da atividade de forrageio foi relacionado mais fortemente e de forma positiva ? luminosidade. O segundo fator mais importante na determina??o do ritmo di?rio de forrageio foi a temperatura, tamb?m relacionada positivamente durante a maior parte do ano. Por ?ltimo, a umidade apresentou uma rela??o fraca e negativa com o ritmo di?rio de forrageio em apenas um m?s de observa??o

A relação entre eletromiografia e força é objeto de numerosos estudos, porém tal relação ainda não está totalmente elucidada e necessita de uma melhor fundamentação. Uma possível razão para as divergências entre esses estudos reside na dificuldade em determinar a força de um músculo individualmente de forma direta. Dentro deste contexto, procurou-se utilizar a análise do sinal eletromiográfico, associada a um modelo biomecânico do segmento articular para a avaliação das forças internas do músculo. O objetivo do presente trabalho é avaliar o comportamento eletromiográfico do músculo quadríceps durante exercícios isométricos e isotônicos concêntricos e correlacioná-lo com a força muscular, calculada através de simulações, usando modelos biomecânicos. Busca-se também uma forma de reconstruir a sobrecarga a que o músculo é submetido durante o exercício isotônico, através do tratamento do sinal eletromiográfico. Para tanto, o exercício isotônico é realizado em baixa velocidade e com pequena sobrecarga, e além disso, utiliza-se o procedimento de normalizar o sinal eletromiográfico ponto-a-ponto. Tal procedimento não possibilitou que a força externa, aplicada pelo membro, fosse obtida a partir do tratamento do sinal eletromiográfico, porém permitiu a correlação da eletromiografia com a força interna, gerada pelo músculo. Verificou-se também que a relação entre eletromiografia e força varia com a posição angular, com a força, com a velocidade de contração muscular e com a velocidade angular. No que se refere às análises da atividade isotônica, uma importante conclusão é que a relação entre eletromiografia e força não é linear; no entanto, quando normalizados pelos seus valores máximos podem ser considerados proporcionais. / The relationship between electromyography and force is largely investigated, however, such relation is not yet fully understood, still requiring better foundation. One of the reasons that might cause discrepancies between studies lies on directly calculating a single muscle force. Our approach handles the electromyographic signal coupled with a biomechanical model of the joint for assessment of internal muscle forces. This study aims at an evaluation of electromyographic behavior of the quadriceps muscle throughout isometric and concentric exercises, relating it to muscle force calculated by means of simulations, using biomechanical models. It is also handled in our study a means of assessing muscle overloading throughout dynamic exercises using eletromiographic signals. Accordingly, the dynamic exercise is undergone at slow speed and low resistance; and the electromyographic signal is normalized angle by angle. The approach did not allow the external force, produced by the limb, be assessed by means of electromyographic treatment, however, it allowed a relation between electromyography with internal force produced by the limb. It is worth mentioning that the electromyography-force relationship undergoes variations according to angular position, to degree of force, to muscle contraction velocity, to angular velocity. As to isotonic activity analysis, one important conclusion is the relation between electromyography and force is non-linear, with the proviso, that when normalized by peak values electromyography and force may be considered proportional.

Mathematical relationships have long been used to describe many aspects of muscle function such as the relationship between muscle force and muscle length, muscle force and velocity of contraction or the degree of muscle activation during a contraction. During this work various mathematical expressions have been employed in order to gain an insight into different aspects of muscle activity. The first part of the work examined whether performing a strength protocol on a dynamometer can lead to an increase in eccentric strength output as well as in the neuromuscular activation of the quadriceps group of muscles that appears inhibited during slow concentric and fast eccentric contractions. Neuromuscular activation was modelled via a three-parameter sigmoid function that was also tested for robustness to perturbations in the maximum activation values. During the second part of the study the "functional" hamstrings to quadriceps ratio H:Qfun was expressed as a function of two variables i.e., angular velocity and joint angle. Initially nine-parameter torque-angular velocity-angle profiles were obtained for the knee extensors and flexors from a group of participants. A theoretical 17- parameter H:Qfun function was then derived for each dataset. Subsequently, a simpler, 6-parameter function was derived, RE = aexp(bωn + cθm)-dω1/2θ2 that best reproduced the original 17-parameter fit. Finally, a six-segment subject specific torque-driven model of the Snatch lift was developed in order to investigate the optimal mechanics of the lift. The model simulated the lift from its initiation until the end of the second pull when the feet of the athlete momentarily leave the platform. The six-segment model comprised of foot, shank, thigh, torso (head + trunk), arm and forearm segments with torque generators at the ankle, knee, hip and shoulder joints respectively. The torque profiles were obtained using an isokinetic dynamometer.

Context: It is common practice to treat musculoskeletal injury acutely with cryotherapy with compression. A tobacco poultice and the SportsWrap are touted as effective acute care treatments, yet are unproven. Objective: Compare four treatments (cryotherapy with compression, compression alone, a tobacco poultice, and the SportsWrap) of an experimentally induced bruise to determine their effectiveness at limiting bruise formation, thereby decreasing overall bruise duration. Design: Randomized, controlled, blinded trial. Setting: Research laboratory. Participants: 64 male participants (height: 180.2±6.4cm, weight: 78.0±16.2kg, age: 22.1±2.8yrs) volunteered. Participants committed to not exercise during participation and were free of medication affecting coagulation or inflammation at least 3 days before and throughout the study. Interventions: Participants were shot in both quadriceps with a tennis ball fired from a tennis ball machine at ~31m/sec from 46cm. Digital pictures were taken of the trauma site immediately before and on days 2, 4, 6, 8, and 10 post-trauma. Within 5 minutes of being shot, participants were randomly assigned to receive 1 of 4 treatments to one of their legs: 1) cryotherapy with compression (applied 5 times separated by 2 hours, compression applied with and without the ice until return on Day 2); 2) compression alone (worn continuously until Day 2); 3) a tobacco poultice (worn for no less than 12 hours, then removed; compression reapplied until Day 2); and 4) the SportsWrap (worn continuously until Day 2). Treatment times reflected clinical practice. Untreated leg served as control. Two raters, blinded to treatment and treatment leg, analyzed each bruise, while a third analyzed an unbruised control area for normalization. Software calculated average pixel values of cyan, magenta, yellow, black, and luminosity for each picture. This analysis was shown to be reliable during pilot data collection (ICC = .77) and has been used previously. Main Outcome Measures: Color difference, a unitless value, was calculated as the difference between the treatment and control legs from the normalized average pixel values. A 2 x 4 x 6 mixed model ANOVA followed by Bonferroni post hoc analysis determined differences between limbs and treatments over time. Results: There was no treatment (F3,60 = .47, P = .70) or limb (F1,60 = .04, P = .84) effect, but there was a day effect (F3.9,234.5 = 6.82, P < .001). The mean color difference values were greater on Days 4 and 6 than Days 0 and 10, and Day 4 was greater than Day 2 (Bonferroni < .05). None of the interactions were significant. Conclusions: Treatment had no effect on the degree of bruising that we produced in this study. We are reluctant to generalize this data to musculoskeletal injury beyond what we caused because of insufficient bruising/too great of variance in bruising.

<p> The interrelationship of force, surface elecrograms (EMG) and joint position for static voluntary contractions of Quadriceps Femoris muscle group in man were investigated before and during partial curarization induced by d-tubocurarine. </p> <p> Four normal male volunteers were studied. Each performed a series of brief isometric contractions (by extension of the lower leg against resistance) at different levels of force and at three knee-joint positions while lying in the supine position. All series were repeated for both a normal state and a partially paralyzed state under the :influence of curare. Torque generated about the knee-joint was measured with a Cybex isokinetic system and the nyoelectric activity of three quadriceps muscles was monitored using bipolar surface electrodes. </p> <p> Traditional parameters of nyoelectric activity (mean-rectified-EMG [MRE], and root-mean-squared-DG [RMSE]) were calculated using a minicomputer (PDPll/34), which had also acquired and processed the data. In addition, EMG power spectra were computed by Fast Fourier Transform techniques in an attempt to provide further insight into the effects of curare on human muscle. </p> <p> In order to provide a basis for comparison of the normal state with the parially curarized state, force-EMG relationships were computed for each subject, muscle, knee-joint angle, and condition. Statistical methods (three-way ANOVA' s) were then employed to both quantify any differences that may have existed between the two states and to identify sources of differences within each state. A similar statistically- based comparison of the power spectra was undertaken utilizing several indices that described the shape of the spectra. A general description of the activities of the quadriceps femoris muscles followed after collating all the information that the surface DIG provided in conjunction with the external forces measured. </p> <p> It was concluded that curare did not have any significant effects on the force-EMG relationship. There appeared to be a slight effect of curare on the power spectra however, with a general trend of increasing lower frequency power. The greatest source of variation of force-EMG relationships and power spectra was attributed to the position of the knee-joint. </p> / Thesis / Master of Engineering (MEngr)