Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n=26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners

Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n=26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners

The influence of anthropometric factors on postural balance: the relationship between body composition and posturographic measurements in young adults

OBJECTIVE: The aim of the present study was to evaluate the influence of anthropometric characteristics and gender on postural balance in adults. One hundred individuals were examined (50 males, 50 females; age range 20-40 years). METHODS: The following body composition measurements were collected (using bone densitometry measurements): fat percentage (% fat), tissue (g), fat (g), lean mass (g), bone mineral content (g), and bone mineral density (g/cm(2)). In addition, the following anthropometric measurements were collected: body mass (kg), height (cm), length of the trunk-cephalic region (cm), length of the lower limbs (cm) and length of the upper limbs (cm). The following indices were calculated: body mass index (kg/m(2)), waist-hip ratio and the support base (cm 2). Also, a postural balance test was performed using posturography variables with open and closed eyes. RESULTS: The analysis revealed poor correlations between postural balance and the anthropometric variables. A multiple linear regression analysis demonstrated that the whole group (female and male) height explained 12% of the medial-lateral displacement, 10% of the speed of oscillation, and 11% of the displacement area. The length of the trunk-cephalic length explained 6% of the displacement in the anteroposterior direction. With eyes closed, the support base and height explained 18% of the medial displacement, and the lateral height explained 10% of the displacement speed and 5% of the scroll area. CONCLUSION: Measured using posturography, the postural balance was only slightly influenced by the anthropometric variables, both with open and closed eyes. Height was the anthropometric variable that most influenced postural balance, both in the whole group and separately for each gender. Postural balance was more influenced by anthropometric factors in males than females

Isokinetic analysis of ankle and ground reaction forces in runners and triathletes

OBJECTIVE: To analyze and compare the vertical component of ground reaction forces and isokinetic muscle parameters for plantar flexion and dorsiflexion of the ankle between long-distance runners, triathletes, and nonathletes. METHODS: Seventy-five males with a mean age of 30.26 (±6.5) years were divided into three groups: a triathlete group (n=26), a long-distance runner group (n = 23), and a non-athlete control group. The kinetic parameters were measured during running using a force platform, and the isokinetic parameters were measured using an isokinetic dynamometer. RESULTS: The non-athlete control group and the triathlete group exhibited smaller vertical forces, a greater ground contact time, and a greater application of force during maximum vertical acceleration than the long-distance runner group. The total work (180º/s) was greater in eccentric dorsiflexion and concentric plantar flexion for the non-athlete control group and the triathlete group than the long-distance runner group. The peak torque (60º/s) was greater in eccentric plantar flexion and concentric dorsiflexion for the control group than the athlete groups. CONCLUSIONS: The athlete groups exhibited less muscle strength and resistance than the control group, and the triathletes exhibited less impact and better endurance performance than the runners

Biomechanical evaluation in runners with Achilles tendinopathy

OBJECTIVES: To evaluate the clinical characteristics, ground reaction force (GRF), and function of the plantar muscles and dorsiflexors of the ankle in runners with and without Achilles tendinopathy (AT) and in nonrunners. METHODS: Seventy-two participants (42 men, 30 women; mean age: 37.3±9.9 years) were enrolled in this crosssectional study and divided into three groups: AT group (ATG, n=24), healthy runners’ group (HRG, n=24), and non-runners’ group (NRG, n=24). Both ankles were evaluated in each group. The American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale was used for clinical and functional evaluation. GRF was evaluated using force plates and muscle strength was evaluated using an isokinetic dynamometer. RESULTS: The AOFAS scores were lower in the ATG. The strike impulse was higher in the ATG than in the HRG and NRG. However, GRF was similar among the groups. The ATG exhibited lower total work at 120o /s speed than the HRG. The peak torque in concentric dorsiflexion was lower in the NRG than in the ATG and HRG. The peak torque and total work in concentric plantar flexion were lower in the NRG than in the ATG. The peak torque and total work in eccentric plantar flexion were lower in the NRG than in the ATG and HRG. CONCLUSION: Runners with AT showed higher strike impulse, lower muscle strength of the plantar flexors, and higher clinical and functional damage

Is 12 months enough to reach function after athletes’ ACL reconstruction: a prospective longitudinal study

Context Anterior Cruciate Ligament (ACL) injury is disabling in several sports because it causes knee instability and functional deficit. Usually, surgical treatments produce the best functional outcomes, however, sometimes they are not always able to fully restore stability and function. Objective: The objective of this study was to evaluate postural balance, muscle strength, and functional performance of young athletes with an ACL injury before and after ACL reconstruction. Design: This was a longitudinal observational prospective study. Method: 74 athletes, 60 men, and 14 women, aged between 16 and 45, divided into two groups: the Group-Lesion of ACL with 34 athletes (24.1 years) and the Group-Control with 40 athletes without ACL lesion (27.7 years old). All volunteers performed posturography, isokinetic dynamometry, and the Hop-Test. The ACL-Group was evaluated before and 12 months after the reconstruction and the control group was evaluated once. Results: The Postoperative ACL Group presented greater limb symmetry, 0.96 (± 0.12), than the preoperative ACL Group, 0.87 (± 0.17), p < 0.01 in the Hop-Test. In the posturography, the displacement area was smaller in the postoperative ACL Group, 19.85 (± 5.74), compared to the preoperative ACL Group, 24.20 (± 8.97), p < 0.01. In isokinetic dynamometry the torque peak was greater in the postoperative ACL Group, 0.91 (± 0.14), than in the preoperative ACL Group, 0.74 (± 0.15), p < 0.01. Conclusion: The functional outcomes increased in ACL reconstruction athletes after 12 months, but not at the same level as in the Control Group. The result indicates an incomplete functional recovery, adaptive changes in postural control after injury, reconstruction, and return to sport

Adaptation to the driving simulator and prediction of the braking time performance, with and without distraction, in older adults and middle-aged adults

Context: Many studies show the importance of evaluating the adaptation time of subjects in a virtual driving environment, looking forwards to a response as closest as a possible real vehicle. Objectives This study aimed to identify and analyze the adaptation to the driving simulator in older adults and middle-aged adults with and without a distraction, and a secondary aim was to identify predictors of safe performance for older adults' drives. Design: Male and female middle-aged adults (n = 62, age = 30.3 ± 7.1 years) and older adults (n = 102, age = 70.4 ± 5.8 years) were evaluated for braking time performance in a driving simulator; cognition performance assessment included the Mini-Mental State Examination; motor evaluation included ankle flexor muscle strength with the isokinetic dynamometer and handgrip strength; the postural balance was evaluated with Timed Up and Go test, with and without a cognitive distraction task. Results: Older adults (men and women) and middle-aged adult women require more time to adapt to the driving simulator. The distractor increases the adaptation time for all groups. The main predictors of braking time for older women are age, muscle strength, and postural balance associated with distraction, and for older men, muscle strength. Conclusions: Age, sex, and distractor interfere in the adaptation of the virtual task of driving in a simulator. The evaluation model developed with multi-domains demonstrated the ability to predict which skills are related to braking time with and without the presence of the distractor

Reliability of isokinetic test measurements of the ankle joint

The isokinetic test of the ankle joint is of great relevance, since it is possible to establish protocols with velocities and modes of contraction similar to those of functional and sports activities. Thus, studies showing the reliability of this tool are needed to assist in the prevention of ankle injuries. Objective: To develop a literature review on studies that addressed the reliability of isokinetic ankle joint tests. Methods: The literature search was performed in Pubmed, Lilacs, Pedro, Scielo, Scopus and Cochrane databases with the scientific descriptors ankle and isokinetic and reliability. Thirty-four articles were identified, four were excluded for not studying humans and 27 were included (10 referring to the reliability of isokinetic tests for ankle inverters and eversors and 17 referring to the reliability of flexor plantar and dorsiflexor tests). Results: The reliability of the isokinetic evaluation of the plantar flexors and dorsiflexors has been described for different dynamometers, positions, modes and populations. Intraclass correlation coefficient values ​​range from 0.55 to 0.98; and that of eversors and inverters range from 0.54 to 0.99, rated in the range of satisfactory to excellent. Conclusion: Isokinetic protocols of the ankle joint should be elaborated according to the recruited musculature and the population (with or without pathology).O teste isocinético do tornozelo tem uma grande relevância, já que é possível estabelecer protocolos com velocidades e modos de contração semelhantes aos das atividades funcionais e esportivas. Desta forma, são necessários estudos que mostram a confiabilidade desta ferramenta para auxiliarem na prevenção de lesões do tornozelo. Objetivo: Elaborar uma revisão de literatura sobre estudos que abordaram a confiabilidade de testes isocinéticos da articulação do tornozelo. Métodos: A busca na literatura foi realizada nas bases de dados Pubmed, Lilacs, Pedro, Scielo, Scopus e Cochrane com os descritores científicos ankle e isokinetic e reliability. Foram identificados 34 artigos, 4 foram excluídos por não estudarem humanos e 27 foram incluídos (10 referentes à confiabilidade de testes isocinéticos para inversores e eversores do tornozelo e 17 referentes à confiabilidade de testes para flexores-plantares e dorsiflexores). Resultados: A confiabilidade da avaliação isocinética dos flexores-plantares e dorsiflexores tem sido descrita para diferentes dinamômetros, posições, modos e populações. Os valores de coeficientes de correlação intraclasse variam de 0,55-0,98; e a de eversores e inversores, variam de 0,54-0,99, classificados na faixa de satisfatório a excelente. Conclusão: Os protocolos isocinéticos da articulação do tornozelo devem ser elaborados de acordo com a musculatura recrutada e com a população (com presença ou não de patologia).&nbsp