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1.
Acta Chir Orthop Traumatol Cech ; 87(1): 17-23, 2020.
Artigo em Tcheco | MEDLINE | ID: mdl-32131966

RESUMO

INTRODUCTION The anterior cruciate ligament (ACL) reconstruction is a tried and tested method in treating knee joint instability which brings valuable results in an acceptable time frame. In the long-term follow-up, however, a higher risk of knee osteoarthritis development is described. One of the possible reasons is considered to be the abnormal kinematics of the operated knee. The purpose of our study was to determine the degree to which the ACL reconstruction helps restore the correct gait cycle compared to the healthy limb. MATERIAL AND METHODS The study included patients after the ACL reconstruction performed in the period from 1 January 2016 to 31 March 2018. With the use of strict criteria, 11 patients were selected for kinematic analysis, who underwent examinations in a gait laboratory and were also evaluated using the Tegner and Lysholm rating systems and the IKDC (International Knee Documentation Committee) knee score, namely preoperatively and at 6 and 12 months postoperatively. The kinematic assessment of gait was carried out using the Vicon MX system with the placement of reflexive markers in line with the Plug-In Gait model. RESULTS The clinical outcomes (namely the score according to Tegner, Lysholm as well as the IKDC) during the first year postoperatively showed a major improvement in knee function and the achievement of the pre-injury activity level. The kinematic analysis revealed lower knee extension at the stance phase and lower overall range of motion of the limb with the injured ACL compared to the healthy limb. The follow-up evaluation at 6 and 12 months postoperatively showed a persisting between-limbs difference in knee extension, whereas the range of motion gradually improved during the year. CONCLUSIONS Although our study confirmed that the ACL reconstruction is an efficient method to treat knee joint instability, it also indicated that even at one year after the ACL reconstruction, the kinematics of the operated knee was not fully restored to the level of the heathy knee. The persisting limb-difference in gait kinematics could contribute to the gradual development of degenerative changes in the operated knee joint. Key words: anterior cruciate ligament deficiency, anterior cruciate ligament reconstruction, knee kinematics during gait, knee osteoarthritis.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Articulação do Joelho , Fenômenos Biomecânicos , Seguimentos , Marcha , Humanos , Articulação do Joelho/fisiologia , Resultado do Tratamento
2.
J Frailty Aging ; 9(1): 30-36, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32150211

RESUMO

BACKGROUND: The mobility of older adults is limited by the compounding effects of vascular health conditions, or vascular risk burden. However, little is known about the role of neuromuscular attributes among those in which vascular risk burden contributes to mobility limitations. OBJECTIVE: We investigated (1) the relationship between the absence/presence of type 2 diabetes, hypertension, and/or obesity and mobility measures and neuromuscular attributes, and (2) whether the association between vascular risk burden and mobility is mediated by lower limb neuromuscular attributes. DESIGN: Cross-sectional analysis of baseline data from 430 older adults within the Boston RISE Study. MEASUREMENTS: Measures of mobility were the Short Physical Performance Battery, habitual gait speed, and functional mobility as measured by the Late Life Function Instrument. We also evaluated lower limb neuromuscular attributes, namely leg strength, leg velocity, trunk extensor muscle endurance, knee and ankle range of motion, and sensory loss. RESULTS: Participants self-reported the presence of None (n=93), One (n=179), Two (n=114), or Three (n=44) of the following conditions: diabetes, hypertension, and obesity. Multivariable regression models indicated that those with a greater vascular risk burden had worse performance on the Short Physical Performance Battery (p=0.01), slower gait speed (p=0.0003) and lower Basic and Advanced Late Life Function Instrument scores (p<0.003). These associations were independent of multiple covariates. Vascular risk burden was also found to be negatively associated with leg strength (p=0.0002) and knee flexion range of motion (p<0.0001) and an associated non-significant trend was observed with leg velocity (p=0.06). In addition, the association between vascular risk burden and mobility outcomes were found to be partially mediated by leg strength, leg velocity, and knee flexion range of motion. CONCLUSIONS: Among older adults with vascular risk burden and mobility problems, neuromuscular impairments in attributes such as leg strength, leg velocity, and knee range of motion may need to be treatment priorities.


Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Hipertensão/epidemiologia , Limitação da Mobilidade , Força Muscular/fisiologia , Obesidade/epidemiologia , Idoso , Estudos Transversais , Humanos , Articulação do Joelho/fisiologia , Perna (Membro)/fisiologia , Amplitude de Movimento Articular/fisiologia , Fatores de Risco
3.
J Sports Sci ; 38(5): 568-575, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32019482

RESUMO

This study aimed to assess the effect of playing surface (Natural [NT] and Artificial [AT] Turf) on the fatigue response to a soccer-specific exercise protocol (SSEP). Eighteen male soccer players completed the SSEP on NT and AT with pre-, post-, and 48 h post-assessments of eccentric knee flexor (eccKF) and concentric knee extensor peak torque (PT), peak countermovement (CMJ) and squat jump (SJ) height, and Nordic hamstring break angle. No significant main effects for surface or any surface and time interactions were observed for any of the outcome measures, except for eccKF PT recorded at 3.14 rad·s-1, which was significantly lower 48 h post-trial in the AT condition (AT = 146.3 ± 20.4 Nm; NT = 158.8 ± 24.7 Nm). Main effects for time were observed between pre- and post-trial measures for eccKF PT at all angular velocities, Nordic break angle, CMJ and SJ height. Nordic break angle, and both CMJ and SJ height were significantly impaired 48 h post-trial when compared to pre-trial. The findings of the current study suggest surface dependent changes in eccKF PT which may have implications for recovery and subsequent performance after competition on AT.


Assuntos
Planejamento Ambiental , Exercício/fisiologia , Articulação do Joelho/fisiologia , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Futebol/fisiologia , Adulto , Desempenho Atlético/fisiologia , Estudos Cross-Over , Músculos Isquiotibiais/fisiologia , Humanos , Masculino , Fenômenos Fisiológicos Musculoesqueléticos , Desempenho Físico Funcional , Amplitude de Movimento Articular , Futebol/lesões , Torque , Adulto Jovem
4.
J Sports Sci ; 38(6): 652-657, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32009512

RESUMO

The purpose of this study was to investigate subject- and joint-specific strategies used by male basketball players as they increase their countermovement jump (CMJ) height from sub-maximal to maximal efforts. Lower extremity joint kinematics and kinetics were recorded as 11 male, NCAA Division I basketball players performed 8-10 CMJ across effort levels of approximately 25%, 50%, 75% and 100%. Simple correlation models were used to investigate the associations between effort levels (i.e., CMJ height) and joint mechanics (i.e., negative (eccentric) and positive (concentric) mechanical work performed at the hip, knee, and ankle joints) for each individual player and the entire group. Group-analyses showed that increases in all joint mechanical variables were associated with increases in CMJ height. In contrast, single-subject analyses revealed that players used individualised strategies, and selectively scaled the magnitude of mechanical work at none (n = 2), one (n = 2), two (n = 5), or all three (n = 2) joints as they increased CMJ efforts. In addition, individual players also appeared to selectively scale different combinations of eccentric or concentric joint work as they increased CMJ height. These results highlight that male basketball players use joint-specific strategies to increase CMJ height when progressively increasing CMJ effort.


Assuntos
Articulação do Tornozelo/fisiologia , Basquetebol/fisiologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Exercício Pliométrico , Fenômenos Biomecânicos , Humanos , Cinética , Masculino , Análise e Desempenho de Tarefas , Adulto Jovem
5.
Int J Sports Med ; 41(3): 182-188, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31902127

RESUMO

Female athletes are at an elevated risk for tearing their anterior cruciate ligament, compared to their male counterparts. Though injury screening clinical tests and neuromuscular training programs have been widely implemented, injury rates remain high among female athletes. The purpose of this study was to examine the relationship between serum relaxin concentrations and knee valgus during three clinical tests (single leg squat, drop vertical jump, and single leg crossover dropdown). Twenty-two female athletes volunteered. Participants were scheduled for collection during the mid-luteal phase, when serum relaxin concentrations are known to be measurable. Blood samples were collected, and serum relaxin concentrations were quantified. Kinematic data were collected while participants performed the three clinical tests. Regression analyses revealed statistically significant relationships between serum relaxin concentrations and knee valgus throughout all tests. These findings suggest that serum relaxin concentrations and knee valgus are not independent of each other and more holistic approaches may be necessary to truly map out the risk for injury and ultimately reduce the rate of anterior cruciate ligament injuries. Thus, concluding that knee valgus, a highly utilized modifiable biomechanical risk factor, and relaxin, a hormone that has been associated with anterior cruciate ligament injury in female athletes, are related to each other.


Assuntos
Articulação do Joelho/fisiologia , Relaxina/sangue , Adolescente , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Lesões do Ligamento Cruzado Anterior/prevenção & controle , Traumatismos em Atletas/fisiopatologia , Traumatismos em Atletas/prevenção & controle , Fenômenos Biomecânicos , Teste de Esforço , Feminino , Humanos , Análise de Regressão , Fatores de Risco , Adulto Jovem
6.
J Sports Sci ; 38(5): 518-527, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31900052

RESUMO

The purpose of this study was to investigate the effects of slope on three-dimensional running kinematics at high speed. Thirteen male sprinters ran at high speed (7.5 m/s) on a motorised treadmill in each a level and a 5.0% slope condition. Three-dimensional motion analysis was conducted to compare centre of mass (CoM) energetics, pelvis segment and lower limb joints kinematics. We found that contact time was not affected by the slope, whereas flight time and step length were significantly shorter in uphill compared to level running. Uphill running reduced negative CoM work and increased positive CoM work compared to level running. Ankle, knee and hip joints were more flexed at initial ground contact, but only the knee was more extended at the end of stance in uphill compared to level running. Additionally, the hip joint was more abducted, and the free leg side of the pelvis was more elevated at the end of stance in uphill running. Our results demonstrate that joint motion must be developed from a more flexed/adducted position at initial contact through a greater range of motion compared to level running in order to meet the greater positive CoM work requirements in uphill running at high speed.


Assuntos
Articulação do Tornozelo/fisiologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Corrida/fisiologia , Fenômenos Biomecânicos/fisiologia , Teste de Esforço , Marcadores Fiduciais , Marcha , Humanos , Imagem Tridimensional , Masculino , Movimento/fisiologia , Amplitude de Movimento Articular/fisiologia , Adulto Jovem
7.
J Sports Sci ; 38(1): 6-12, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31603027

RESUMO

This study aimed to examine the characteristics of electromyography (EMG) and kinematics of the supporting leg affecting energy cost while running at incline, level, and decline slopes. Twelve male Japanese middle- and long-distance runners volunteered for this study. The subjects were asked to run at 13.5 km·h-1 on a treadmill under three slope conditions. Sagittal plane kinematics and the EMG of the lower limb muscles, respiratory gases were recorded. Energy cost differed significantly between slopes, being the lowest in decline slope and the greatest in incline slope. Integrated EMG (iEMG) of leg extensor muscles was greater in the incline slope than in the decline slope, and iEMG of the gastrocnemius and soleus muscles correlated positively with energy cost. The knee and ankle joint kinematics were associated with energy cost during running. In incline slope, the knee and ankle joints were more extended (plantarflexed) to lift the body. These movements may disturb the coordination between the ankle and knee joints. The gastrocnemius muscle would do greater mechanical work to plantarflex the ankle joint rather than transfer mechanical energy as well as greater mechanical work of mono-articular muscles. These muscular activities would increase energy cost.


Assuntos
Metabolismo Energético/fisiologia , Extremidade Inferior/fisiologia , Corrida/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Eletromiografia , Teste de Esforço/métodos , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Movimento/fisiologia , Músculo Esquelético/fisiologia , Troca Gasosa Pulmonar/fisiologia , Adulto Jovem
8.
Sports Biomech ; 19(2): 245-257, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29920153

RESUMO

Knee functional disorders are one of the most common lower extremity non-traumatic injuries reported by cyclists. Incorrect bicycle configuration may predispose cyclist to injury but the evidence of an effect of saddle setback on knee pain remains inconclusive. The aim of this study was to determine the effect of saddle setback on knee joint forces during pedalling using a musculoskeletal modelling approach. Ten cyclists were assessed under three saddle setback conditions (range of changes in saddle position ~6 cm) while pedalling at a steady power output of 200 W and cadence of 90 rpm. A cycling musculoskeletal model was developed and knee joint forces were estimated using an inverse dynamics method associated with a static optimisation procedure. Our results indicate that moving the saddle forwards was not associated with an increase of patellofemoral joint forces. On the contrary, the tibiofemoral mean and peak compression force were 14 and 15% higher in the Backward than in the Forward condition, respectively. The peak compression force was related to neither pedal force nor quadriceps muscle force but coincided with the eccentric contraction of knee flexor muscles. These findings should benefit bike fitting practitioners and coaches in the design of specific training/rehabilitation protocols.


Assuntos
Ciclismo/fisiologia , Articulação do Joelho/fisiologia , Equipamentos Esportivos , Adulto , Artralgia/fisiopatologia , Ciclismo/lesões , Fenômenos Biomecânicos , Desenho de Equipamento , Humanos , Masculino , Contração Muscular/fisiologia , Articulação Patelofemoral/fisiologia , Músculo Quadríceps/fisiologia
9.
Sports Biomech ; 19(2): 189-200, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29768121

RESUMO

Cerebral palsy is known to generally limit range of motion and force producing capability during movement. It also limits sprint performance, but the exact mechanisms underpinning this are not well known. One elite male T36 multiple-Paralympic sprint medallist (T36) and 16 well-trained able-bodied (AB) sprinters each performed 5-6 maximal sprints from starting blocks. Whole-body kinematics (250 Hz) in the block phase and first two steps, and synchronised external forces (1,000 Hz) in the first stance phase after block exit were combined to quantify lower limb joint kinetics. Sprint performance (normalised average horizontal external power in the first stance after block exit) was lower in T36 compared to AB. T36 had lower extensor range of motion and peak extensor angular velocity at all lower limb joints in the first stance after block exit. Positive work produced at the knee and hip joints in the first stance was lower in T36 than AB, and the ratio of positive:negative ankle work produced was lower in T36 than AB. These novel results directly demonstrate the manner in which cerebral palsy limits performance in a competition-specific sprint acceleration movement, thereby improving understanding of the factors that may limit performance in elite sprinters with cerebral palsy.


Assuntos
Aceleração , Desempenho Atlético/fisiologia , Paralisia Cerebral/fisiopatologia , Extremidade Inferior/fisiologia , Corrida/fisiologia , Esportes para Pessoas com Deficiência/fisiologia , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Amplitude de Movimento Articular , Adulto Jovem
10.
Gait Posture ; 75: 72-77, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31606722

RESUMO

BACKGROUND: Running-related musculoskeletal injuries are common. Knee injuries are most frequent, and often occur during or shortly after marathons. RESEARCH QUESTION: The effects of a marathon on runners' knee kinematics remain unclear. No studies have shown comprehensive three-dimensional (3D) knee kinematic changes following a marathon. This study aimed to observe the effects of running a marathon on 3D knee kinematics and identify the phases of walking and running gait in which significant changes occur. METHODS: Based on an electronic survey, 10 healthy, recreational runners (20 knees) with similar running experience were included. Their 3D knee kinematics (during treadmill walking and running) were collected using a portable, optical motion capture system within 24 h before and within 6 h after running a marathon. RESULTS: All measurements after the marathon were compared with pre-marathon measurements. (1) For walking post-marathon: varus rotation increased by 1.8° [95% confidence interval (CI) 0.1-3.4, P = 0.036] at peak knee extension during stance; anterior translation increased by 2.2 mm (95% CI 0.3-4.1, P = 0.025) at initial contact; range of motion (ROM) in internal-external rotation increased less than 1°, P = 0.023; ROM in anteroposterior translation increased by 3.8 mm, P = 0.048. (2) For running post-marathon: flexion rotation increased by 1.6° (95% CI 0.2-2.9, P = 0.025) at initial contact; varus rotation increased by 2.0° (95% CI 0.2-3.8, P = 0.031) at peak knee extension during stance. SIGNIFICANCE: Significant differences in varus rotation and anterior translation were identified following a marathon, which could potentially contribute to injury. These results provide important information for runners and coaches about knee kinematic alterations following a marathon.


Assuntos
Joelho/fisiologia , Corrida/fisiologia , Caminhada/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Joelho/fisiopatologia , Traumatismos do Joelho/etiologia , Traumatismos do Joelho/fisiopatologia , Traumatismos do Joelho/prevenção & controle , Articulação do Joelho/fisiologia , Articulação do Joelho/fisiopatologia , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Rotação , Corrida/lesões
11.
J Sports Sci ; 38(5): 486-493, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31865835

RESUMO

Biomechanical analysis has typically been confined to a laboratory setting. While attempts have been made to take laboratory testing into the field, this study was designed to assess whether augmented reality (AR) could be used to bring the field into the laboratory. This study aimed to measure knee load in volleyball players through a jump task incorporating AR while maintaining the perception-action couplings by replicating the visual features of a volleyball court. Twelve male volleyball athletes completed four tasks: drop landing, hop jump, spike jump, and spike jump while wearing AR smart glasses. Biomechanical variables included patellar tendon force, knee moment and kinematics of the ankle, knee, hip, pelvis and thorax. The drop landing showed differences in patellar tendon force and knee moment when compared to the other conditions. The hop jump did not present differences in kinetics when compared to the spike conditions, instead of displaying the greatest kinematic differences. As a measure of patellar tendon loading the AR condition showed a close approximation to the spike jump, with no differences present when comparing landing forces and mechanics. Thus, AR may be used in a clinical assessment to better replicate information from the competitive environment.


Assuntos
Desempenho Atlético/fisiologia , Realidade Aumentada , Voleibol/fisiologia , Adolescente , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos/fisiologia , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Ligamento Patelar/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
12.
Clin Sports Med ; 39(1): 1-12, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31767101

RESUMO

The menisci are 2 fibrocartilaginous crescents anchored via bony and ligamentous attachments to surrounding structures. Their biochemical composition and multilayered structure make them ideal for converting compressive forces to tensile forces in addition to improving joint congruity and providing shock absorption to weight bearing. The medial meniscus maintains more attachments at both the horns and the midbody than the lateral meniscus, making it more susceptible to injury. Understanding of the gross anatomy, vascular anatomy, biochemical composition, and microstructure is key to understanding causes of meniscal pathology as well as treatment options for restoring its primary functions.


Assuntos
Meniscos Tibiais/anatomia & histologia , Meniscos Tibiais/fisiologia , Água Corporal/metabolismo , Colágeno Tipo I/metabolismo , Colágeno Tipo II/metabolismo , Glicosaminoglicanos/metabolismo , Humanos , Articulação do Joelho/anatomia & histologia , Articulação do Joelho/fisiologia , Propriocepção/fisiologia , Proteoglicanas/metabolismo , Líquido Sinovial/fisiologia , Lesões do Menisco Tibial/fisiopatologia , Suporte de Carga/fisiologia
13.
J Sports Sci Med ; 18(4): 663-668, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31827350

RESUMO

The purpose of this study was to investigate the mechanical similarity between net joint moments (NJM) of the countermovement jump (CMJ) and the hang power clean (HPC) and jump shrug (JS). Twelve male Lacrosse players performed three maximal effort CMJs and three repetitions of the HPC and JS at 30%, 50%, and 70% of their HPC one repetition maximum (1-RM). Ground reaction forces and motion capture data were used to calculate the NJM of the hip, knee, and ankle joints during each exercise. Statistical comparison of the peak NJM indicated that NJM during the HPC and JS across all loads were equal to or greater than the NJM during the CMJ (all p < 0.025). In addition, correlation analyses indicated that CMJ hip NJM were associated (all p < 0.025) with HPC hip NJM at 30% and 70% (r = 0.611-0.822) and JS hip NJM at 50% and 70% (r = 0.674-0.739), whereas CMJ knee NJM were associated with HPC knee NJM at 70% (r = 0.638) and JS knee NJM at 50% and 70% (r = 0.664-0.732). Further, CMJ ankle NJM were associated with HPC ankle NJM at 30% and 50% (r = 0.615-0.697) and JS ankle NJM at 30%, 50%, and 70% (r = 0.735-0.824). Lastly, knee and ankle NJM during the JS were greater than during the HPC at 30% and 50% of 1-RM (all p < 0.017). The degree of mechanical similarity between the CMJ and the HPC and JS is dependent on the respective load and joint.


Assuntos
Articulação do Tornozelo/fisiologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Exercício Pliométrico , Levantamento de Peso/fisiologia , Estudos Transversais , Humanos , Cinética , Masculino , Esportes com Raquete/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
14.
Hum Mov Sci ; 68: 102528, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31706119

RESUMO

The objective of this study was to characterize joint angle variation across strides. Specifically, the statistical persistence of variations were quantified using the Hurst exponent. If a time series exhibits statistical persistence, then a parameter which is smaller (or larger) than average will tend to be followed by additional values that are also smaller (or larger) than average. Human walking has statistical persistence between stride durations. Variation in stride duration must arise from variation in the motion of the leg segments during walking. It is unclear, however, if the joint angle variation also exhibits statistical persistence. This study examined kinematic data collected from nine healthy adults walking for 10 min at a self-selected comfortable speed on a treadmill. The joint angle variation in the lower limbs was parameterized using first-order Fourier series which in turn were described by frequency and magnitude coefficients for each stride. To determine if the joint angle variation exhibited statistical persistence, the Hurst exponent was found for each coefficient at each joint. The mean Hurst exponents were 0.54 for the frequency coefficients and 0.61 for the magnitude coefficients. Neither the frequency or magnitude coefficients exhibited statistically significant persistence, although some of the magnitude coefficients were close to reaching statistical significance. This suggests that joint angle variability in healthy adults does not directly produce the statistical persistence observed in stride duration fluctuations.


Assuntos
Articulação do Quadril/fisiologia , Caminhada/fisiologia , Adolescente , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos/fisiologia , Teste de Esforço/métodos , Feminino , Marcha/fisiologia , Humanos , Articulação do Joelho/fisiologia , Extremidade Inferior/fisiologia , Masculino , Amplitude de Movimento Articular/fisiologia , Adulto Jovem
15.
J Sports Med Phys Fitness ; 59(10): 1684-1690, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31694362

RESUMO

BACKGROUND: Athletes in jumping and running sports have a high incidence of Achilles tendon (AT) injuries. We compared AT loading during jumping and landing phases in anteroposterior (AP) and mediolateral (ML) directions. METHODS: Sixteen males (age: 21.6±1.8 years, height: 178.4±6.4 cm, weight: 76.4±11.2 kg) performed single leg AP and ML jump-landings during both propulsive (jump) and braking (land) phases. Inverse dynamics and static optimization were used to determine muscle forces. AT cross sectional area was measured with ultrasound. AT force was divided by cross sectional area to determine stress while strain was determined from previous data. Two-way repeated measures analysis of variance (α=0.05) compared several variables (vertical ground reaction force (VGRF), ankle and knee angle, ankle joint muscle moment arm, external ankle moment arm, AT tendon force, stress, and strain) between movements (jump-landings) and directions (AP/ML). RESULTS: AT loading was higher during jump than land in the ML compared to AP direction. VGRF was higher during land versus jump with no direction effect (AP/ML). An interaction showed a higher VGRF during the AP land and ML jump. The ankle joint moment arm was lower in jump and AP direction at peak tendon stress. External ankle moment arm at peak tendon stress was higher in jump and ML direction with an interaction. A larger external ankle moment arm occurred in ML but the change was less in the jump. CONCLUSIONS: Higher tendon loading occurred during the jump and ML direction. This may provide insight into both injuries and rehabilitation efforts.


Assuntos
Tendão do Calcâneo/química , Tendão do Calcâneo/fisiologia , Adulto , Traumatismos do Tornozelo , Articulação do Tornozelo/fisiologia , Atletas , Fenômenos Biomecânicos/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Movimento , Corrida , Adulto Jovem
16.
Hum Mov Sci ; 68: 102521, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610993

RESUMO

This study examined biomechanical differences between external and internal foci of attention during vertical jump landings in males and females. Twenty-four healthy adults performed eight vertical jump landings using both internal and external foci while three-dimensional kinematic and ground reaction force (GRF) data were obtained. Two (focus) by two (sex) analyses of variance (α = 0.05) and Cohen's d effect sizes (ES) were used to compare differences in vertical GRF, joint angular positions and displacements, and lower limb joint angular work between foci and between sexes. Significantly greater knee contributions to total angular work occurred during external versus internal focus landings regardless of sex (p = .013; ES = 0.30). Significantly smaller plantarflexion angles (p = .019; ES = 0.53) and significantly greater knee flexion angles were observed at ground contact (p < .001; ES = 1.11) in males during external focus landings. Females exhibited significantly smaller knee flexion angles at both ground contact during external versus internal focus landings (p = .031; ES = 0.20) and compared to males during external focus landings (p < .001; ES = 1.76). Both peak vertical GRF (p = .003; ES = 1.54) and the ankle contributions to total angular work during loading (p = .026; ES = 1.07) were greater in females versus males regardless of foci, whereas the knee contributions to total angular work during loading were smaller in women (p = .026; ES = 1.07). Males and females might consider adopting an external focus during vertical jump landings to increase knee joint contributions to lower limb energy absorption. Females, in particular, might consider external focus use to decrease peak vertical GRF and increase the knee joint's contribution to total energy absorption to magnitudes similar to those exhibited by males.


Assuntos
Atenção/fisiologia , Extremidade Inferior/fisiologia , Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Articulação do Tornozelo , Fenômenos Biomecânicos/fisiologia , Feminino , Humanos , Articulação do Joelho/fisiologia , Masculino , Amplitude de Movimento Articular/fisiologia , Caracteres Sexuais
17.
Med Sci Monit ; 25: 7720-7727, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31611547

RESUMO

BACKGROUND Unbalanced standing and gait asymmetry are common in individuals with musculoskeletal disorders. Achieving symmetrical posture and gait is an important goal of rehabilitation. This study investigated the biomechanical differences in the lower extremities observed immediately after an insole was used and without the use of different one-sided insoles. MATERIAL AND METHODS Thirty young, healthy adult males received 3 different insole interventions: experimental group A had a customized 3-dimensional (3D)-printed single-sided lateral wedge insole (CLWI) inserted on the left side, and experimental group B had on the left side, a traditional single insert. The control had unilateral flat insoles; no insole inserted into the socks. Motion mechanics and gait parameters were collected at the 2-time points, after insertion of the insole and after 20 minutes of walking with the insole. RESULTS Asymmetric posture and gait appeared immediately after using the 2 insoles (lower joint moment, P<0.05). Compared with the control group, the abnormal posture and gait of experimental group B after wearing the traditional insole for 20 minutes were not obvious (P>0.05). However, the asymmetrical posture and gait remained in experimental group A after wearing the CLWI for 20 minutes (P<0.05). The center of pressure (COP) trajectory of the left foot of experimental group A was significantly higher than that of experimental group B and the control group at the 2-time points (P<0.05). CONCLUSIONS The asymmetry of posture and gait can be observed in a short time using a customized 3D-printed single-sided lateral wedge insole. This experiment provides guidance for the application of customized 3D-printed single-sided lateral wedge insoles for gait rehabilitation.


Assuntos
Órtoses do Pé/tendências , Marcha/fisiologia , Postura/fisiologia , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , China , Pé/fisiologia , Voluntários Saudáveis , Humanos , Articulação do Joelho/fisiologia , Extremidade Inferior/fisiologia , Masculino , Impressão Tridimensional , Caminhada/fisiologia
18.
Sensors (Basel) ; 19(19)2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31569372

RESUMO

Overweight/obesity is a physical condition that affects daily activities, including walking. The main purpose of this study was to identify if there is a relationship between body mass index (BMI) and gait characteristics in young adults. 12 normal weight (NW) and 10 overweight/obese (OW) individuals walked at a self-selected speed along a 14 m indoor path. H-Gait system, combining seven inertial sensors (fixed on pelvis and lower limbs), was used to record gait data. Walking speed, spatio-temporal parameters and joint kinematics in 3D were analyzed. Differences between NW and OW and correlations between BMI and gait parameters were evaluated. Conventional spatio-temporal parameters did not show statistical differences between the two groups or correlations with the BMI. However, significant results were pointed out for the joint kinematics. OW showed greater hip joint angles in frontal and transverse planes, with respect to NW. In the transverse plane, OW showed a greater knee opening angle and a shorter length of knee and ankle trajectories. Correlations were found between BMI and kinematic parameters in the frontal and transverse planes. Despite some phenomena such as soft tissue artifact and kinematics cross-talk, which have to be more deeply assessed, current results show a relationship between BMI and gait characteristics in young adults that should be looked at in osteoarthritis prevention.


Assuntos
Índice de Massa Corporal , Marcha/fisiologia , Monitorização Fisiológica/instrumentação , Sobrepeso , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Humanos , Articulação do Joelho/fisiologia , Masculino , Monitorização Fisiológica/métodos , Sobrepeso/fisiopatologia , Análise Espaço-Temporal , Caminhada/fisiologia
19.
Int J Sports Med ; 40(13): 863-870, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31593991

RESUMO

Previous cross-sectional studies have reported that higher drop heights do not always result in improved performance, and may increase injury risk during drop jumps (DJ). The purpose of this study was to analyze the kinematics and kinetics during the DJ in order to determine the relative drop height that maximize performance without exposing the lower extremity joints to unnecessary loads. Twenty male Division I college volleyball players volunteered. Data were collected using 11 infrared cameras and two force platforms. Participants performed three maximal effort countermovement jumps (CMJ). Subsequently, 50, 75, 100, 125, and 150% CMJ height (CMJH) was used to scale their relative drop height for three DJ trials per height. There was a significant increase in the landing phase impulse when the drop height exceeded 100%CMJH (p<0.05). At 125% and 150%CMJH, the negative work of knee and ankle significantly increased. The incoming velocity, kinetic energy, landing depth, maximum ground reaction force, landing impulse and power absorption of knee and ankle all increased with drop height (p<0.05). DJ height and reactive strength index following the drop landing were not statistically different between any of the drop heights (p>0.05). 50% to 100%CMJH may be the appropriate individual relative drop height for the DJ.


Assuntos
Extremidade Inferior/fisiologia , Exercício Pliométrico , Voleibol/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Estudos Transversais , Articulação do Quadril/fisiologia , Humanos , Cinética , Articulação do Joelho/fisiologia , Masculino , Estudos de Tempo e Movimento , Adulto Jovem
20.
Gait Posture ; 74: 242-249, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31574408

RESUMO

BACKGROUND: Excessive foot pronation during running in individuals with foot varus alignment may be reduced by medially wedged insoles. RESEARCH QUESTION: This study investigated the effects of a medially wedged insole at the forefoot and at the rearfoot on the lower limbs angles and internal moments of runners with excessive foot pronation and foot varus alignment. METHODS: Kinematic and kinetic data of 19 runners (11 females and 8 males) were collected while they ran wearing flat (control condition) and medially wedged insoles (insole condition). Both insoles had arch support. We used principal component analysis for data reduction and dependent t-test to compare differences between conditions. RESULTS: The insole condition reduced ankle eversion (p = 0.003; effect size = 0.63); reduced knee range of motion in the transverse plane (p = 0.012; effect size = 0.55); increased knee range of motion in the frontal plane in early stance and had earlier knee adduction peak (p = 0.018; effect size = 0.52); reduced hip range of motion in the transverse plane (p = 0.031; effect size = 0.48); reduced hip adduction (p = 0.024; effect size = 0.50); reduced ankle inversion moment (p = 0.012; effect size = 0.55); and increased the difference between the knee internal rotation moment in early stance and midstance (p = 0.012; effect size = 0.55). SIGNIFICANCE: Insoles with 7˚ medial wedges at the forefoot and rearfoot are able to modify motion and moments patterns that are related to lower limb injuries in runners with increased foot pronation and foot varus alignment with some non-desired effects on the knee motion in the frontal plane.


Assuntos
Órtoses do Pé , Pé/fisiologia , Extremidade Inferior/fisiologia , Pronação/fisiologia , Corrida/fisiologia , Sapatos , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Feminino , Articulação do Quadril/fisiologia , Humanos , Cinética , Articulação do Joelho/fisiologia , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Amplitude de Movimento Articular
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