scholarly journals Do Surface Slope and Posture Influence Lower Extremity Joint Kinetics during Cycling?

2020 ◽  
Vol 17 (8) ◽  
pp. 2846
Author(s):  
Yunqi Tang ◽  
Donghai Wang ◽  
Yong Wang ◽  
Keyi Yin ◽  
Cui Zhang ◽  
...  
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Repeated Measures ◽  
Reaction Force ◽  
Standing Position ◽  
The Body ◽  
Body Posture ◽  
Mechanical Work ◽  
Surface Slope ◽  
Joint Kinetics

The purpose of this study was to investigate the effects of surface slope and body posture (i.e., seated and standing) on lower extremity joint kinetics during cycling. Fourteen participants cycled at 250 watts power in three cycling conditions: level seated, uphill seated and uphill standing at a 14% slope. A motion analysis system and custom instrumented pedal were used to collect the data of fifteen consecutive cycles of kinematics and pedal reaction force. One crank cycle was equally divided into four phases (90° for each phase). A two-factor repeated measures MANOVA was used to examine the effects of the slope and posture on the selected variables. Results showed that both slope and posture influenced joint moments and mechanical work in the hip, knee and ankle joints (p < 0.05). Specifically, the relative contribution of the knee joint to the total mechanical work increased when the body posture changed from a seated position to a standing position. In conclusion, both surface slope and body posture significantly influenced the lower extremity joint kinetics during cycling. Besides the hip joint, the knee joint also played the role as the power source during uphill standing cycling in the early downstroke phase. Therefore, adopting a standing posture for more power output during uphill cycling is recommended, but not for long periods, in view of the risk of knee injury.

scholarly journals Lower Limb Joint Kinetics During Moderately Sloped Running

2010 ◽  
Vol 45 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Gaurav Telhan ◽  
Jason R. Franz ◽  
Jay Dicharry ◽  
Robert P. Wilder ◽  
Patrick O. Riley ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Ground Reaction Force ◽  
Injury Risk ◽  
Reaction Force ◽  
Surface Slope ◽  
Joint Moments ◽  
Joint Kinetics ◽  
3 Dimensional ◽  
Modifiable Factors ◽  
The Impact

Abstract Context: Knowledge of the kinetic changes that occur during sloped running is important in understanding the adaptive gait-control mechanisms at work and can provide additional information about the poorly understood relationship between injury and changes in kinetic forces in the lower extremity. A study of these potential kinetic changes merits consideration, because training and return-to-activity programs are potentially modifiable factors for tissue stress and injury risk. Objective: To contribute further to the understanding of hill running by quantifying the 3-dimensional alterations in joint kinetics during moderately sloped decline, level, and incline running in a group of healthy runners. Design: Crossover study. Setting: Three-dimensional motion analysis laboratory. Patients or Other Participants: Nineteen healthy young runners/joggers (age  =  25.3 ± 2.5 years). Intervention(s): Participants ran at 3.13 m/s on a treadmill under the following 3 different running-surface slope conditions: 4° decline, level, and 4° incline. Main Outcome Measure(s): Lower extremity joint moments and powers and the 3 components of the ground reaction force. Results: Moderate changes in running-surface slope had a minimal effect on ankle, knee, and hip joint kinetics when velocity was held constant. Only changes in knee power absorption (increased with decline-slope running) and hip power (increased generation on incline-slope running and increased absorption on decline-slope running in early stance) were noted. We observed an increase only in the impact peak of the vertical ground reaction force component during decline-slope running, whereas the nonvertical components displayed no differences. Conclusions: Running style modifications associated with running on moderate slopes did not manifest as changes in 3-dimensional joint moments or in the active peaks of the ground reaction force. Our data indicate that running on level and moderately inclined slopes appears to be a safe component of training regimens and return-to-run protocols after injury.

7. Frontal Plane Knee Loading during Bodyweight Squat Performance: Effects of Stance Width and Foot Rotation

2016 ◽  
Author(s):  
David Kingston
Keyword(s):  
Body Weight ◽  
Knee Joint ◽  
Repeated Measures ◽  
Inverse Dynamics ◽  
Exercise Prescription ◽  
Reaction Force ◽  
Frontal Plane ◽  
The Body ◽  
Knee Adduction Moment ◽  
Squat Exercise

The bodyweight squat is routinely used for conditioning of the knee musculature. In the performance of this exercise, modifications in the initial standing position may result in altered frontal plane kneel loading, and hence may potentially be used for targeted exercise prescription. The purpose of this study is to quantify the frontal plane mechanical loading on the knee joint whilst performing the bodyweight squat exercise, and to examine the effects of varying stance width and foot rotation angle. Twenty-four participants (14 males) performed 4 randomized sets of 8 repetitions of the body weight resistant squat exercise in the following conditions: 1) Shoulder width (SW) stance with parallel feet; 2) SW stance with feet externally rotated 30°; 3) 140% SW stance with parallel feet, and; 4) 140% SW stance with the feet externally rotated by 30°. The adduction/abduction knee joint moment experienced across conditions was calculated using inverse dynamics procedures. Moment waveforms were subjected to Principal Component (PC) analysis, with 3 PC’s retained based on a 90% trace criteria. Following, a 1-way repeated measures ANOVA and pair wise comparisons were used to discern differences between conditions. Omnibus test results indicate significant differences across conditions for PC1 and PC2 (p<0.01), Post hoc comparisons and waveform interpretation of PC1 extreme scores showed that the magnitude of the adduction moment was higher throughout the movement in the foot rotated conditions vs. the parallel feet conditions in both stance widths (mean Z scores .69 & .65 vs. -.88 & -.45, p<0.01, respectively). For PC2, significant differences were found between the 2 parallel feet conditions and the 2 foot rotated conditions, as well as between the foot conditions in the wide stance squats. PC2 differences were interpreted as phase shift operators. We found that modification of foot rotation slightly alters the magnitude and timing of knee adduction moment component during performance of the body weight squat. The observed magnitude differences are presumably a consequence of alteration in the location of the point of application of the ground reaction force during the initial standing posture. The findings may assist clinicians in exercise prescription decision making.

Single-Leg Landing Strategy after Knee-Joint Cryotherapy

2005 ◽  
Vol 14 (4) ◽  
pp. 313-320 ◽  
Author(s):  
Joseph M. Hart ◽  
Jamie L. Leonard ◽  
Christopher D. Ingersoll
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Outcome Measures ◽  
Ground Reaction Force ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Reaction Force ◽  
Lower Extremity Function ◽  
Vertical Ground Reaction Force ◽  
Joint Flexion

Context:Despite recent findings regarding lower extremity function after cryotherapy, little is known of the neuromuscular, kinetic, and kinematic changes that might occur during functional tasks.Objective:To evaluate changes in ground-reaction forces, muscle activity, and knee-joint flexion during single-leg landings after 20-minute knee-joint cryotherapy.Design:1 × 4 repeated-measures, time-series design.Setting:Research laboratory.Patients or Other Participants:20 healthy male and female subjects.Intervention:Subjects performed 5 single-leg landings before, immediately after, and 15 and 30 minutes after knee-joint cryo-therapy.Main Outcome Measures:Ground-reaction force, knee-joint flexion, and muscle activity of the gastrocnemius, hamstrings, quadriceps, and gluteus medius.Results:Cryotherapy did not significantly (P> .05) change maximum knee-joint flexion, vertical ground-reaction force, or average muscle activity during a single-leg landing.Conclusion:Knee-joint cryotherapy might not place the lower extremity at risk for injury during landing.

Effects of Saddle Height, Pedaling Cadence, and Workload on Joint Kinetics and Kinematics During Cycling

2010 ◽  
Vol 19 (3) ◽  
pp. 301-314 ◽  
Author(s):  
Rodrigo R. Bini ◽  
Aline C. Tamborindeguy ◽  
Carlos B. Mota
Keyword(s):  
Knee Joint ◽  
Ankle Joint ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Cruciate Ligament ◽  
Joint Kinematics ◽  
Mechanical Work ◽  
Joint Power ◽  
Joint Kinetics ◽  
Work Distribution

Context:It is not clear how noncyclists control joint power and kinematics in different mechanical setups (saddle height, workload, and pedaling cadence). Joint mechanical work contribution and kinematics analysis could improve our comprehension of the coordinative pattern of noncyclists and provide evidence for bicycle setup to prevent injury.Objective:To compare joint mechanical work distribution and kinematics at different saddle heights, workloads, and pedaling cadences.Design:Quantitative experimental research based on repeated measures.Setting:Research laboratory.patients:9 healthy male participants 22 to 36 years old without competitive cycling experience.Intervention:Cycling on an ergometer in the following setups: 3 saddle heights (reference, 100% of trochanteric height; high, + 3 cm; and low, − 3 cm), 2 pedaling cadences (40 and 70 rpm), and 3 workloads (0, 5, and 10 N of braking force).Main Outcome Measures:Joint kinematics, joint mechanical work, and mechanical work contribution of the joints.Results:There was an increased contribution of the ankle joint (P = .04) to the total mechanical work with increasing saddle height (from low to high) and pedaling cadence (from 40 to 70 rpm, P < .01). Knee work contribution increased when saddle height was changed from high to low (P < .01). Ankle-, knee-, and hip-joint kinematics were affected by saddle height changes (P < .01).Conclusions:At the high saddle position it could be inferred that the ankle joint compensated for the reduced knee-joint work contribution, which was probably effective for minimizing soft-tissue damage in the knee joint (eg, anterior cruciate ligament and patellofemoral cartilage). The increase in ankle work contribution and changes in joint kinematics associated with changes in pedaling cadence have been suggested to indicate poor pedaling-movement skill.

Elevated Knee Joint Kinetics and Reduced Ankle Kinetics Are Present During Jogging and Hopping After Achilles Tendon Ruptures

2017 ◽  
Vol 45 (5) ◽  
pp. 1124-1133 ◽  
Author(s):  
Richard W. Willy ◽  
Annelie Brorsson ◽  
Hayley C. Powell ◽  
John D. Willson ◽  
Roy Tranberg ◽  
...  
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Achilles Tendon ◽  
Patellofemoral Joint ◽  
Tendon Rupture ◽  
Achilles Tendon Rupture ◽  
Joint Power ◽  
Joint Stress ◽  
Joint Kinetics ◽  
Joint Loads

Background: Deficits in plantarflexor function are common after an Achilles tendon rupture. These deficits may result in an altered distribution of joint loads during lower extremity tasks. Hypothesis: We hypothesized that, regardless of treatment, the Achilles tendon–ruptured limb would exhibit deficits in ankle kinematics and joint power while exhibiting elevated knee joint power and patellofemoral joint loads during walking, jogging, and hopping. We further hypothesized that this loading pattern would be most evident during jogging and hopping. Study Design: Controlled laboratory study. Methods: Thirty-four participants (17 participants treated surgically, 17 treated nonsurgically) were tested at a mean 6.1 ± 2.0 years after an Achilles tendon rupture. Lower extremity kinematics and kinetics were assessed while participants completed walking, jogging, and single-legged hopping trials. Patellofemoral joint stress was calculated via a musculoskeletal model. Data were analyzed via mixed-model repeated analyses of variance (α = .05) and the limb symmetry index (LSI). Results: No differences ( P ≥ .05) were found between the surgical and nonsurgical groups. In both groups, large side-to-side deficits in the plantarflexion angle at toeoff (LSI: 53.5%-73.9%) were noted during walking, jogging, and hopping in the involved limb. Side-to-side deficits in the angular velocity were only present during jogging (LSI: 93.5%) and hopping (LSI: 92.5%). This pattern was accompanied by large deficits in eccentric (LSI: 80.8%-94.7%) and concentric (LSI: 82.2%-84.7%) ankle joint powers in the involved limb during all tasks. Interestingly, only jogging and hopping demonstrated greater knee joint loads when compared with the uninvolved limb. Concentric knee power was greater during jogging (LSI: 117.2%) and hopping (LSI: 115.9%) compared with the uninvolved limb. Similarly, peak patellofemoral joint stress was greater in the involved limb during jogging (LSI: 107.5%) and hopping (LSI: 107.1%), while only hopping had a greater loading rate of patellofemoral joint stress (LSI: 110.9%). Conclusion: Considerable side-to-side deficits in plantarflexor function were observed during walking, jogging, and hopping in patients after an Achilles tendon rupture. As a possible compensation, increased knee joint loads were present but only during jogging and hopping. Clinical Relevance: These data suggest that after an Achilles tendon rupture, patients may be susceptible to greater mechanical loading of the knee during sporting tasks, regardless of surgical or nonsurgical treatment.

scholarly journals Relationship between Unilateral Posterior Crossbite and Human Static Body Posture

2020 ◽  
Vol 17 (15) ◽  
pp. 5303
Author(s):  
Jorge Zurita-Hernandez ◽  
Raul Ayuso-Montero ◽  
Meritxell Cuartero-Balana ◽  
Eva Willaert ◽  
Jordi Martinez-Gomis
Keyword(s):  
Repeated Measures ◽  
Linear Models ◽  
Standing Position ◽  
Visual Input ◽  
Body Posture ◽  
Foot Pressure ◽  
Horizontal Alignment ◽  
Posterior Crossbite ◽  
Mandibular Position ◽  
Static Body

Background: We compared photogrammetry-assessed body posture between young adults with and without unilateral posterior crossbite (UPCB). Assessments were controlled by vision, mandibular position and sitting/standing position. In addition, we aimed to determine the relationship between UPCB laterality and the direction of body posture using photogrammetry and a static postural platform. Methods: Adults with natural dentition, with and without UPCB, were enrolled. Static body posture was assessed by photogrammetry based on horizontal acromial alignment and horizontal anterior-superior iliac spine (ASIS) alignment. Frontal photographs were taken with participants asked to open or close their eyes and hold their jaws at rest, at an intercuspal position, and at left or right lateral positions. Distribution of foot pressure was recorded using a static postural platform at different visual input and mandibular positions. General linear models with repeated measures were used to assess the effect of the various within- and between-subject factors. Results: In total, 36 adults (left UPCB = 12; Right UPCB = 6; controls = 18) participated. There were significant differences between the control and UPCB groups in horizontal alignment at the acromion (p = 0.035) and ASIS (p = 0.026) levels when controlled by visual input and mandibular position. No significant differences in horizontal alignment or foot pressure distribution were observed by laterality in the UPCB group. Conclusion: The presence of UPCB affects static body posture, but the side of crossbite is not related to the direction of effect on static body posture.

Modeling of Knee Joint in The Human Lower Extremity by Using Cam-Follower and Revolute-Translational Composite Joint

1996 ◽  
Vol 8 (2) ◽  
pp. 211-216
Author(s):  
P. Eko Purwanto ◽  
◽  
Shigeki Toyama ◽  
Atsuhiko Kamijima
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Muscle Force ◽  
Translational Motion ◽  
Reaction Force ◽  
Joint Model ◽  
Inertia Moment ◽  
Composite Joint ◽  
Cam Follower ◽  
Reaction Torque

This paper presents a musculoskeletal model of the human lower extremity for computer simulation studies of the knee joint during movement. In this model, we developed a knee joint model by using a combination of cam-follower joint and revolute-translational composite joint. The cam-follower joint is used, where femur is the cam and tibia is the follower, to determine the reaction force as well as the reaction torque (the reaction torque cannot be calculated in the revolute joint). Furthermore the revolute-translational composite joint is used to represent the movement of the knee joint that undergoes revolute motion as well as translational motion. The estimation of muscle force is then developed from the moment of the joint that consists of moment of inertia, moment of external force, and moment resulting from the effect of gravity. In the walking motion analysis, simulation results then indicate the validity of the knee joint model and the estimation of muscle force. We therefore conclude that the use of cam-follower and revolute-translational composite joint in the knee joint model is useful to express the motion in the knee joint and to estimate force in the muscles in the lower extremity.

scholarly journals Optimization-Based Biomechanical Evaluation of Isometric Exertions on a Brake Wheel

1993 ◽  
Vol 37 (10) ◽  
pp. 693-696 ◽  
Author(s):  
Christian A. Johnson ◽  
Jeffrey C. Woldstad
Keyword(s):  
Repeated Measures ◽  
Three Dimensional ◽  
Compressive Force ◽  
Biomechanical Model ◽  
The Body ◽  
Body Posture ◽  
Muscle Forces ◽  
Left Hand ◽  
Lumbar Muscle ◽  
External Forces

A static three-dimensional low-back biomechanical model was developed to estimate the levels of compressive force on the L3/L4 spinal joint during an experiment that simulated wheel turning. We recorded three-dimensional body posture and the resultant forces at the hands for analysis by the model. The model employed a standard link analysis procedure to resolve the external forces acting on the body to a resultant moment about L3/L4. The model then implemented an optimization algorithm to estimate the internal lumbar muscle forces generated to resist the external forces. The muscle forces and external forces were added to arrive at a prediction of compressive force at L3/L4. The experiment investigated the effects of general body posture, left hand grip, gender, and hand brake torque level upon predicted compressive force at L3/L4. A repeated measures analysis of variance (ANOVA) revealed all but one main effect and some interaction effects to be significant at p<0.05. Average predicted L3/L4 compressive forces at maximum wheel torque levels ranged from 1644N for females to 6926N for large males.

The effect of carrying a light shoulder bag and cross bag on trunk positioning in young adults

2020 ◽  
Vol 30 (90) ◽  
pp. 55-62
Author(s):  
Michał Fałatowicz ◽  
Agnieszka Jankowicz-Szymańska ◽  
Angelika Kaczor
Keyword(s):  
Repeated Measures ◽  
Thoracic Kyphosis ◽  
Sagittal Plane ◽  
Statistical Significance ◽  
The Body ◽  
Body Posture ◽  
Rank Test ◽  
Small Load ◽  
Data Compilation ◽  
The Way

Introduction: Postural defects and accompanying dysfunctions are one of the greatest existing health problems. It is necessary to define factors responsible for the formation of incorrect body posture and strive to eliminate or modify them. The aim of the study was to determine changes in trunk positioning depending on the way of carrying a small handbag (the bag weighing 2.7 kg). Materials and methods: The study comprised 32 volunteers aged 21.75±2.00 years. The ZEBRIS Pointer system was used to test the body posture. The Statistica v13 program was applied for data compilation. Normality of distribution regarding variables was tested with the Shapiro-Wilk test. Differences between repeated measures were estimated using ANOVA, Friedman’s rank test and post hoc tests. The level of statistical significance was α=0.05. Results: Placing the bag on one shoulder significantly increased thoracic kyphosis, while wearing the bag diagonally across the trunk caused a significant increase in both thoracic kyphosis and lumbar lordosis. Other observed changes concerned the balance of the trunk in the sagittal plane, the position of the shoulder blades, symmetry of shoulder position and pelvic rotation. Conclusions: Carrying even a small load in the form of a bag significantly changes quality of body posture. Furthermore, changes in body posture depend on the way of carrying the load. Wearing the bag diagonally across the trunk is not better than carrying it asymmetrically on one shoulder.

Influence of External Ankle Support on Lower Extremity Joint Mechanics During Drop Landings

2010 ◽  
Vol 19 (2) ◽  
pp. 136-148 ◽  
Author(s):  
Mitchell L. Cordova ◽  
Yosuke Takahashi ◽  
Gregory M. Kress ◽  
Jody B. Brucker ◽  
Alfred E. Finch
Keyword(s):  
Knee Joint ◽  
Lower Extremity ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Angular Displacement ◽  
Joint Mechanics ◽  
Drop Landing ◽  
Joint Displacement ◽  
Ankle Support ◽  
Drop Landings

Objective:To investigate the effects of external ankle support (EAS) on lower extremity joint mechanics and vertical ground-reaction forces (VGRF) during drop landings.Design:A 1 × 3 repeated-measures, crossover design.Setting:Biomechanics research laboratory.Patients:13 male recreationally active basketball players (age 22.3 ± 2.2 y, height 177.5 ± 7.5 cm, mass 72.2 ± 11.4 kg) free from lower extremity pathology for the 12 mo before the study.Interventions:Subjects performed a 1-legged drop landing from a standardized height under 3 different ankle-support conditions.Main Outcome Measures:Hip, knee, and ankle angular displacement along with specific temporal (TGRFz1, TGRFz2; s) and spatial (GRFz1, GRFz2; body-weight units [BW]) characteristics of the VGRF vector were measured during a drop landing.Results:The tape condition (1.08 ± 0.09 BW) demonstrated less GRFz1 than the control (1.28 ± 0.16 BW) and semirigid conditions (1.28 ± 0.21 BW; P < .0001), and GRFz2 was unaffected. For TGRFz1, no-support displayed slower time (0.017 ± 0.004 s) than the semirigid (0.014 ± 0.001 s) and tape conditions (0.014 ± 0.002 s; P < .05). For TGRFz2, no-support displayed slower time (0.054 ±.006 s) than the semirigid (0.050 ± 0.006 s) and tape conditions (0.045 ± 0.004 s; P < .05). Semirigid bracing was slower than the tape condition, as well (P < .05). Ankle-joint displacement was less in the tape (34.6° ± 7.7°) and semirigid (36.8° ± 9.3°) conditions than in no-support (45.7° ± 7.3°; P < .05). Knee-joint displacement was larger in the no-support (45.1° ± 9.0°) than in the semirigid (42.6° ± 6.8°; P < .05) condition. Tape support (43.8° ± 8.7°) did not differ from the semirigid condition (P > .05). Hip angular displacement was not affected by EAS (F2,24 = 1.47, P = .25).Conclusions:EAS reduces ankle- and knee-joint displacement, which appear to influence the spatial and temporal characteristics of GRFz1 during drop landings.

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