3D Joint Moments Research Articles

The influence of gearing footwear on running biomechanics

The influence of nonlinear bending stiffness footwear, which alters the metatarsophalangeal (MTP) joint bending as a function of forefoot bending stiffness, has been postulated to improve athletic performance and reduce injury risk during many sports. As the shoe moves through greater amounts of bending, forefoot stiffness should increase nonlinearly, to shift the centre of pressure forward (improving performance), while restricting forefoot bending in regions where turf toe injury may result. Recently, materials which allow for stiffness modifications as a function of forefoot flexion angle have been developed; however, the efficacy of this technology is unknown. Therefore, the purpose of this project was to evaluate the influence of gearing technology (a variable bending stiffness shoe) on biomechanics during running and sprinting. Ten male recreational athletes performed running and sprinting in two footwear conditions consisting of an altered US 10 adidas 16.4 FXG cleat. The footwear was altered by placing carbon fibre insoles with variable (nonlinear stiffness) into the shoes creating two different conditions: Control (no insole) and the variable stiffness (varStiff) shoe (gearing insoles). Kinematic (joint angles) and kinetic (ground reaction force and 3D joint moments) data of the lower extremity were recorded during each movement. The results of the study indicate that the variable stiffness insoles did positively influence athlete lower extremity biomechanics. At the MTP joint, as running speed increased (and normal MTP bending range of motion increased), the variable stiffness insoles reduced the amount of MTP bending of the shoes and reduced the medial–lateral movement of the point of force application. Additionally, the variable stiffness insoles reduced key biomechanical injury risk variables, such as non-sagittal plane joint loading at the knee and ankle joint.

Comparison of Three Normalization Methods for 3D Joint Moment in the Asymmetric Rotational Human Movements in Golf Swing Analysis

th , 2015; Revised: August 11 st , 2015; Accepted: August 20 th , 2015 Purpose: From the perspective of biomechanics, joint moments quantitatively show a subject’s ability to perform actions. In this study, the effect of normalization in the fast and asymmetric motions of a golf swing was investigated by applying three different normalization methods to the raw joint moment. Methods: The study included 13 subjects with no previous history of musculoskeletal diseases. Golf swing analyses were performed with six infrared cameras and two force plates. The majority of the raw peak joint moments showed a significant correlation at p < 0.05. Additionally, the resulting effects after applying body weight (BW), body weight multiplied by height (BWH), and body weight multiplied by leg length (BWL) normalization methods were analyzed through correlation and regression analysis. Results: The BW, BWH, and BWL normalization methods normalized 8, 10, and 11 peak joint moments out of 18, respectively. The best method for normalizing the golf swing was found to be the BWL method, which showed significant statistical differences. Several raw peak joint moments showed no significant correlation with measured anthropometrics, which was considered to be related to the muscle coordination that occurs in the swing of skilled professional golfers. Conclusions: The results of this study show that the BWL normalization method can effectively remove differences due to physical characteristics in the golf swing analysis.

Biomechanical maturation of joint dynamics during early childhood: Updated conclusions

Dynamic parameters have been commonly explored to characterize the biomechanical maturation of children's gaits, i.e., age-revealing joint moment and power patterns similar to adult patterns. However, the literature revealed a large disparity of conclusions about maturation depending on the study, which was most likely due to an inappropriate scaling strategy and uncontrolled walking speed. With the first years of independent walking, a large growth in height and a large variability of dimensionless walking speed are observed. Moreover, the dynamic parameters were not well studied during early childhood.In the present study, seventy-five healthy children between 1 and 6 years of age were assessed during gait trials at a self-selected speed. Four hundred and sixty-two gait trials constituting five age groups with comparable dimensionless walking speeds were selected. 3D joint moments and the power of the lower limbs were computed and expressed using a dimensionless scaling strategy (according to body weight, leg length and the acceleration of gravity). Statistical analysis was performed to examine inter-group differences. Based on the current results, we concluded the biomechanical maturation of joint dynamics occurred around an age of 4 years for the ankle and between 6 and 7 years for the knee and the hip. Moreover, age group comparisons seemed more appropriate in young children using both the dimensionless strategy and a similar walking speed. Future investigations will be conducted on an older population (i.e., adding children older than 6 years) to clearly define the status of knee and hip biomechanical maturation.

Expression of Joint Moment in the Joint Coordinate System

The question of using the nonorthogonal joint coordinate system (JCS) to report joint moments has risen in the literature. However, the expression of joint moments in a nonorthogonal system is still confusing. The purpose of this paper is to present a method to express any 3D vector in a nonorthogonal coordinate system. The interpretation of these expressions in the JCS is clarified and an example for the 3D joint moment vector at the shoulder and the knee is given. A nonorthogonal projection method is proposed based on the mixed product. These nonorthogonal projections represent, for a 3D joint moment vector, the net mechanical action on the JCS axes. Considering the net mechanical action on each axis seems important in order to assess joint resistance in the JCS. The orthogonal projections of the same 3D joint moment vector on the JCS axes can be characterized as "motor torque." However, this interpretation is dependent on the chosen kinematic model. The nonorthogonal and orthogonal projections of shoulder joint moment during wheelchair propulsion and knee joint moment during walking were compared using root mean squares (rmss). rmss showed differences ranging from 6 N m to 22.3 N m between both projections at the shoulder, while differences ranged from 0.8 N m to 3.0 N m at the knee. Generally, orthogonal projections were of lower amplitudes than nonorthogonal projections at both joints. The orthogonal projection on the proximal or distal coordinates systems represents the net mechanical actions on each axis, which is not the case for the orthogonal projection (i.e., motor torque) on JCS axes. In order to represent the net action at the joint in a JCS, the nonorthogonal projection should be used.

Extrinsic foot muscle forces when running in varus, valgus and neutral wedged shoes

The role of the extrinsic foot muscles in controlling the foot during the period of eversion is not well understood. The major extrinsic muscles are: tibialis anterior, tibialis posterior, gastrocnemius, peroneals, soleus and extensor digitorum longus. The purpose of this study was to investigate the role of the extrinsic foot muscles in running in response to perturbations caused by neutral, varus and valgus wedged footwear. Twelve healthy, college aged males ran with a heel–toe footfall pattern at 3.6 m s−1± 5% in the specially constructed footwear. Three-dimensional kinematic and kinetic data were collected and used in a Newton–Euler inverse dynamics calculation to determine 3D joint moments. We used a static optimization approach which employed the ankle joint moments and a minimization cost function to determine the individual muscle forces. Of the six extrinsic foot muscles, only the extensor digitorum longus (dorsiflexor) and the peroneals (evertor) resulted in force differences among footwear conditions. Neither of these muscles act to resist the eversion action. There were differences in the muscle force between wedge conditions in the extensor digitorum longus, peroneals and the tibialis anterior and posterior. Again, none of these muscles resist eversion. These results indicate that the extrinsic foot muscles experience small alterations as a result of the wedged footwear during the support phase of running.

3D joint dynamics analysis of healthy children's gait

The 3D joint moments and 2D joint powers have been largely explored in the literature of healthy children's gait, in particular to compare them with pathologic subjects’ gait. However, no study reported on 3D joint power in children which could be due to the difficulties in interpreting the results. Recently, the analysis of the 3D angle between the joint moment and the joint angular velocity vectors has been proposed in order to help 3D joint power interpretation. Our hypothesis is that this 3D angle may help in characterizing the level of gait maturation. The present study explores 3D joint moments, 3D joint power and the proposed 3D angle for both children's and adults’ gaits to highlight differences in the strategies used. The results seem to confirm that children have an alternative strategy of mainly ankle stabilization and hip propulsion compared to the adults’ strategy of mainly ankle resistance and propulsion and hip stabilization. In the future, the same 3D angle analysis should be applied to different age groups for better describing the evolution of the 3D joint dynamic strategies during the growth.

Méthodes biomécaniques avancées pour le calcul des moments articulaires et des forces musculaires

Taking into account the growing number of musculoskeletal pathologies, more and more clinical studies are nowadays based on the evaluation of the 3D joint moments. The calculation of these joint moments requires a rigorous experimental protocol set-up, and the development of advanced kinematic and inverse dynamic methods, taking into account the functional centres and axes and the personalized inertial characteristics of the subject. Moreover, starting from the measurement of the lever arms of the muscles and implementing a numerical technique for optimization, it is possible to improve the analysis in order to evaluate the muscular forces and the contact forces on the joints.

Errors in the Measurement of Center of Pressure (CoP) Computed with Force Plate Affect on 3D Lower Limb Joint Moment During Gait

The purpose of this study was to investigate the effect of errors in the center of pressure (CoP) locations on three-dimensional (3D) lower limb joint moments during the stance phase of gait. Kinematic and kinetic data were collected from walking trials of one healthy male subject (age: 22yr, height: 181cm, body mass: 80kg). Changes of 3D joint moment were calculated using inverse dynamics with 3D video analysis and ground reaction force (GRF) measurement. Thereafter, the location of the CoP was shifted toward the antero-posterior/medio-lateral direction by ±10mm, ±20mm and ±30mm, respectively, and 3D joint moments were recalculated with the shifted CoP data. As a result of the simulated shift of the CoP in the antero-posterior direction, changes of magnitude in the ankle (dorsiflexion-plantarflexion), knee (flexion-extension), and hip joint moments (flexion-extension) were observed, while the moment patterns did not change. Simulated CoP shift in the medio-lateral direction altered the magnitude of the hip joint moment (abduction-adduction, internal-external rotation). Moreover it greatly affected the change of the inversion-eversion ankle joint moment. A shift of ±10mm of CoP in the medio-lateral direction reversed joint moment pattern of ankle joint inversion-eversion. The joint moment magnitudes and patterns were more sensitive to errors in the medio-lateral direction than in the antero-posterior direction, largely due to differences in the moment arm length and the direction of the GRF. This clearly illustrates the need to accurately determine CoP position in the calculation of lower limb joint kinetics.

Aging Effect on Joint Moment Generation Strategy in Successful Reactive-Recovery from Unexpected Slips

3D joint moment analysis has been regarded as a valuable tool in slips and falls studies. In addition to the commonly used peak joint moments, joint moment distribution characteristics enabled by 3D approach may reflect the relative importance of different anatomical planes. The objective of this study was to examine the aging effect on lower extremity joint moment distribution characteristics among all the three anatomical planes during the process of successful reactive-recovery from unexpected slips. Nine young and nine old participants who were identified as having successful recovery trials were selected from previously conducted walking experiments. Unexpected slips were created by introducing slippery floor surface without participants' awareness. Peak joint moment ratio (JMP Ratio) was defined and computed for each anatomical plane. Results indicated significant decreased sagittal JMP Ratio for the old group and significant increased sagittal JMP Ratio for the young group during recovery. It was concluded that young and old individuals appeared to adopt different joint moment distribution strategies, which may be due to age-related lower extremity strength degradation.

Comparison of 3D joint moments using local and global inverse dynamics approaches among three different age groups

A complete understanding of joint moment is important to locomotion research. The purpose of the study was to compare stance phase lower extremity joint moments, calculated by a three-dimensional (3D) inverse dynamics model and expressed in global and local coordinate systems, to examine the influence of different coordinate systems on joint moment profiles. Additionally, aging influences on joint moments were examined. Thirty healthy (10 young, 10 middle-aged and 10 old) participants were involved in the current study. Kinematic and kinetic data were collected using standard gait study protocol. Results suggested that globally expressed joint moments were significantly different than those expressed locally. Furthermore, significant moment differences were found between young and old age groups. The older adults produced less evertor muscle moments at the ankle joint. However, aging effect was not significant for majority of the joint moment comparisons. It is concluded that coordinate system need to be carefully chosen, and specified in 3D joint moment analysis, while significant error introduced by using 2D analysis need to be considered.

Role of Ankle Joint in Successful Reactive-Recovery: A 3D Joint Moment Analysis

Understanding successful reactive-recovery is essential to further exploration of slip induced fall event. The objective of the current study was to characterize the net ankle joint moment pattern during reactive-recovery process. Six out of fifteen healthy young adults were selected as input for the current investigation. The three-dimensional (3D) inverse dynamics approach was applied to calculate net ankle joint moments in all the three planes (frontal, sagittal and transverse). Gait conditions (normal and reactive-recovery) significantly affected the absolute ankle peak moment and time to peak at p ≤ 0.05 level. The time to peak in the ankle frontal plane was the only one not affected. The ankle frontal and transverse joint moment was found to play an important role during the reactive-recovery process. Consequently, the necessity of a complete 3D joint moment analysis especially for slip and fall incidents was justified.