PubMed HealthSearch

Biomedical subjects

B M Nigg

Publications and source records attributed to B M Nigg.

At least 19 recordsLinked to original sources

Contribution of the lower extremity joints to mechanical energy in running vertical jumps and running long jumps.

The energy contribution of the lower extremity joints to vertical jumping and long jumping from a standing position has previously been investigated. However, the resultant joint moment contributions to vertical and long jumps performed with a running approach are unknown. Also, the contribution of the metatarsophalangeal joint to these activities has not been investigated. The objective of this study was to determine the mechanical energy contributions of the hip, knee, ankle and metatarsophalangeal joints to running long jumps and running vertical jumps. A sagittal plane analysis was performed on five male university basketball players while performing running vertical jumps and four male long jumpers while performing running long jumps. The resultant joint moment and power patterns at the ankle, knee and hip were similar to those reported in the literature for standing jumps. It appears that the movement pattern of the jumps is not influenced by an increase in horizontal velocity before take-off. The metatarsophalangeal joint was a large energy absorber and generated only a minimal amount of energy at take-off. The ankle joint was the largest energy generator and absorber for both jumps; however, it played a smaller relative role during long jumping as the energy contribution of the hip increased.

Adult

Effect of shoe insert construction on foot and leg movement.

PURPOSE: The purpose of this study was to quantify changes in foot eversion and tibial rotation during running resulting from systematic changes of material composition of five shoe inserts of the same shape. METHODS: Tests were performed with 12 subjects. The inserts had a bilayer design using two different materials at the top and bottom of the insert. The functional kinematic variables examined in this study were the foot-leg in-eversion angle, beta, and the leg-foot tibial rotation, rho. Additionally, the subject characteristics of arch height, relative arch deformation, and active range of motion were quantified. The statistical analysis used was a two way repeated measures MANOVA (within trials and inserts). RESULTS: The average group changes resulting from the studied inserts in total shoe eversion, total foot eversion, and total internal tibial rotation were typically smaller than 1 degree when compared with the no-insert condition and were statistically not significant. The measured ranges of total foot eversion for all subjects were smallest for the softest and about twice as large for the hardest insert construction. Thus, the soft insert construction was more restrictive, forcing all feet into a similar movement pattern, whereas the harder combinations allowed for more individual variation of foot and leg movement and did not force the foot into a preset movement pattern. The individual results showed substantial differences between subjects and a trend: Subjects who generally showed a reduction of tibial rotation with all tested inserts typically had a flexible foot. However, subjects who generally showed an increase of tibial rotation typically had a stiff foot. CONCLUSIONS: The results of this study suggest that subject specific factors such as static, dynamic, and neuro-physiological characteristics of foot and leg are important to match specific feet and shoe inserts optimally.

Adult

Pronation in runners. Implications for injuries.

In spite of some significant progress in the understanding of the biomechanics of the ankle joint complex, especially the coupling mechanism between foot and leg, various mechanisms causing overuse injuries in the lower extremities are still poorly understood. Some increased pronation of the foot is often physiological, but excessive pronation is potentially harmful. Compensatory overpronation may occur for anatomical reasons. However, not only the amount of foot eversion, but also the way this eversion is transferred into tibial rotation may be crucial to the overloading stress on the knee. In other words, the individual transfer mechanism of foot eversion into internal tibial rotation may be of some predictable value for lower extremity overloading and related injuries. Further research is necessary to improve the functional understanding of anatomical and biomechanical abnormalities and their pathological value in predicting overuse injuries.

Ankle Injuries

A method to determine bone movement in the ankle joint complex in vitro.

An experimental set-up has been developed to quantify motion of bone structures in the ankle joint complex of human cadaver specimens under conditions approximating physiological joint loading. The device allows to load the foot/leg specimen along the axis of the tibia, and muscle forces can be simulated by clamping the extrinsic tendons of the foot. Additionally, an axial moment can be applied to the tibia. A variety of foot movements can be induced by rotating a foot plate around an arbitrary axis in the horizontal plane. The input force which produces the movement at the foot is applied to the entire sole of the foot. A forefoot fixation allows for the natural adaptation of the midfoot and hindfoot which occurs during loading of the specimen. Bone pins were placed in the tibia, talus, calcaneus and navicular, and three reflective markers were attached to each pin in order to record the bone movements with a video system. Intersegmental rotations in the talo-crural, talo-calcaneal, and talo-navicular joints were calculated in three dimensions, compared for different loading and ligament integrity conditions, and related to a functionally/anatomically described foot position. Repeated measurements of relative bone orientations indicated a reproducibility better than 2 degrees; the slope of the curves, representing the kinematic coupling, was virtually identical between repetitions. It is proposed that this method simulates multidirectional AJC compression similar to loading situations during locomotion.

Aged

Effect of skin movement on the analysis of skeletal knee joint motion during running.

It is not known how well skin markers represent the skeletal knee joint motion during running. Hence the purpose of this investigation was to compare the skin marker derived tibiofemoral motion with the skeletal tibiofemoral motion during running. In addition to skin markers attached to the shank and thigh, triads of reflective markers were attached to bone pins inserted into the tibia and femur. Three-dimensional kinematics of the stance phase of five running trials were recorded for three subjects using high-speed cine cameras (200 Hz). The knee motion was expressed in terms of Cardan angles calculated from both the external and skeletal markers. Good agreement was present between the skin and bone marker based knee flexion/extension. For abduction/adduction and internal/external knee rotation, the difference between skeletal and external motion was large compared to the amplitude of these motions. Average errors relative to the range of motion during running stance were 21% for flexion/extension, 63% for internal/external rotation, and 70% for abduction/adduction. The errors were highly subject dependent preventing the realization of a successful correction algorithm. It was concluded that knee rotations other than flexion/extension may be affected with substantial errors when using skin markers.

Adult

Assessment of the mechanical properties of area-elastic sport surfaces with video analysis.

Mechanical properties of a surface are assumed to be of importance with respect to injuries, comfort, and performance in sport. For a better understanding of the factors that do influence the etiology of injuries as well as comfort, a method was developed to compare mechanical characteristics of wooden area-elastic indoor surfaces. The method was based on video analysis of markers mounted on the surface during tests using human subjects performing movements. The method provided information concerning deflection, area-elasticity, and vibration. With the proposed methodology it was possible to detect differences with respect to these variables in differently built wooden sport surfaces. The accuracy of the analysis was greater than 0.1 mm. The results show that it was possible to use the proposed methodology in the assessment of the area-elastic wooden sport surfaces. This information may be at help in understanding the relation between surface characteristics and surface-related injuries, comfort, and possible fatigue.

Elasticity

A method for inverse dynamic analysis using accelerometry.

A method was developed to calculate total resultant force and moment on a body segment, in three dimensions, from accelerometer data. The method was applied for an analysis of intersegmental loading at the hip joint during the single support phase of working and running, using four triaxial accelerometers mounted on the upper body. Results were compared to a conventional analysis using simultaneously recorded kinematics and ground reaction forces. The loading patterns obtained by both methods were similar, but the accelerometry method systematically underestimated the intersegmental force and moment at the hip by about 20%. This could be explained by the inertial and gravitational forces originating from the swing leg which were neglected in the analysis. In addition, the accelerometry analysis was not not reliable during the impact phase of running, when the upper body and accelerometers did not behave as a rigid body. For applications where these limitations are acceptable, the accelerometry method has the advantage that it does not require a gait laboratory environment and can be used for field studies with a completely body-mounted recording system. The method does not require differentiation or integration, and therefore provided the possibility of real-time inverse dynamics analysis.

Acceleration

Influence of ankle ligaments on tibial rotation: an in vitro study.

The purpose of this study was to clarify the role of the ankle ligaments in controlling the tibial rotation for different foot positions. A 6 degrees of freedom device was constructed for in vitro simulation of this movement transfer during the support phase of gait. Tibia rotation angle was measured for different foot positions and vertical loads, while the ligament integrity was modified. Data were collected from eight legs of four different cadavers. The results showed that vertical loading is unimportant to influence tibial rotation, while the lateral ankle ligaments have significant influence, especially during eversion. It was concluded that chronic partial or total lateral ankle instability may contribute to knee and foot injuries through abnormal tibial rotation.

Aged

The effect of an ankle orthosis on ankle range of motion and performance.

Ankle joint orthoses are used for rehabilitation and/or prevention of ankle sprains. The purpose of this study was to determine the effect of the Malleoloc ankle joint orthosis on active and passive range of motion reduction and on a jumping and a figure-eight running test. Twelve subjects with a history of inversion ankle sprain and documented increased anterior translation in a drawer test participated in the study. Active and passive range of motion for inversion was determined with and without the orthosis and pre- and post-exercise. Additionally, performance tests for figure-eight running and jumping were administered. The results showed that the tested orthosis 1) restricted the active range of motion and passive inversion substantially, 2) reduced the other movement degrees of freedom only minimally, 3) provided the same movement restriction before and after exercise, and 4) did not affect performance. The Malleoloc ankle joint orthoses can, therefore, restrict ankle joint motion without affecting performance negatively.

Adult

Direct dynamics simulation of the impact phase in heel-toe running.

The influence of muscle activation, position and velocities of body segments at touchdown and surface properties on impact forces during heel-toe running was investigated using a direct dynamics simulation technique. The runner was represented by a two-dimensional four- (rigid body) segment musculo-skeletal model. Incorporated into the muscle model were activation dynamics, force-length and force-velocity characteristics of seven major muscle groups of the lower extremities: mm. glutei, hamstrings, m. rectus femoris, mm. vasti, m. gastrocnemius, m. soleus and m. tibialis anterior. The vertical force-deformation characteristics of heel, shoe and ground were modeled by a non-linear visco-elastic element. The maximum of a typical simulated impact force was 1.6 times body weight. The influence of muscle activation was examined by generating muscle stimulation combinations which produce the same (experimentally determined) resultant joint moments at heelstrike. Simulated impact peak forces with these different combinations of muscle stimulation levels varied less than 10%. Without this restriction on initial joint moments, muscle activation had potentially a much larger effect on impact force. Impact peak force was to a great extent influenced by plantar flexion (85 N per degree of change in foot angle) and vertical velocity of the heel (212 N per 0.1 m s-1 change in velocity) at touchdown. Initial knee flexion (68 N per degree of change in leg angle) also played a role in the absorption of impact. Increased surface stiffness resulted in higher impact peak forces (60 N mm-1 decrease in deformation).(ABSTRACT TRUNCATED AT 250 WORDS)

Ankle Joint

Reliability and validity of active, passive and dynamic range of motion tests.

The purposes of this project were to determine (a) the reliability of ROM and POM assessment methods for tests where an ankle joint brace was used and (b) the relationship between active and passive ROM and POM inversion measurements. The range of motion of the ankle joint complex for inversion was quantified using a range of motion apparatus. The inversion path of motion for the foot and the shoe was quantified using a high speed video system. The results of this study indicated: (a) Comprehensive functional tests of ankle joint braces using ROM and POM measurements showed maximal group differences of less than 1 degree between days for ROM (rAROM = 0.96 and rPROM = 0.93) and less than 1.5 degrees for POM measurements (rPOM = 0.88). (b) PROM measurements showed a consistent "creep" effect of about 2 degrees with increasing trial number during the first ten trials which must be taken into consideration for the design of the appropriate test protocol. (c) The correlation coefficient between AROM and POM was 0.37 and 0.44 between PROM and POM, suggesting that AROM and PROM measurements do not predict inversion during actual movement.

Adult

In vitro kinematics of the axially loaded ankle complex in response to dorsiflexion and plantarflexion.

The rotational movements of the tibia and calcaneus that occur with dorsiflexion-plantarflexion and axial loading were studied in cadaver foot-leg specimens using an unconstrained testing apparatus. Independent of the foot flexion position, significant internal rotation of the tibia and eversion of the calcaneus were noted after the ankle complex was axially loaded. Independent of loading, 10 degrees of dorsiflexion resulted in 0.1 degrees of eversion and 2.1 degrees of internal rotation of the tibia. Conversely, 10 degrees of plantarflexion resulted in 1.6 degrees of inversion and 1.3 degrees of external rotation of the tibia. The induced rotational movements of the tibia and the calcaneus differed significantly between the specimens. These results suggest that the foot "axes" did not change by axially loading the ankle complex and they support previous reports that the ankle complex uses different axes for dorsiflexion and plantarflexion.

Aged

Influence of ligament transection on tibial and calcaneal rotation with loading and dorsi-plantarflexion.

The purpose of this study was to quantify the effect of sequential ligament transection (anterior talofibular, calcaneofibular, posterior talofibular, deltoid, and subtalar interosseous ligaments) on the rotational movement of the tibia and the calcaneus as associated with axial loading and dorsi-plantarflexing the foot. Eight cadaver foot-leg specimens were investigated using a unconstrained testing apparatus. As the ankle complex was axially loaded, almost the same internal rotation of the tibia and the same calcaneus eversion was found with and without the various degrees of lateral and medial ligament release; additional sectioning of the subtalar interosseous ligament tremendously increased the resulting tibial and calcaneal rotation. While tibial and calcaneal rotation from foot dorsi-plantarflexing did not alter significantly with transection of the lateral ligaments, almost no tibial and calcaneal rotation occurred after additional sectioning of the deltoid and subtalar interosseous ligament. These results indicate that, after release of the lateral ligaments, the foot becomes partially mechanically disconnected from the tibia by additional transection of the medial ligaments and even further disconnected after transection of the subtalar interosseous ligament.

Aged

Influence of arthrodeses on kinematics of the axially loaded ankle complex during dorsiflexion/plantarflexion.

The purpose of this study was to quantify the effect of selective arthrodesis (stabilization) of the ankle, subtalar, and talonavicular joints on the rotational movement of the tibia and the calcaneus occurring with dorsiflexion/plantarflexion. Six cadaver foot-leg specimens were investigated using an unconstrained testing apparatus. Simulated ankle joint arthrodesis caused a large increase in tibial rotation and calcaneal eversion-inversion. Subtalar and talonavicular stabilization did not cause as large a rotation.

Aged

Influence of heel height on ankle joint moments in running.

Clinically, heel lifting or heel wedging in running shoes has been proposed as a prevention and treatment of Achilles tendinitis. It has been speculated that heel lifting decreases the Achilles tendon forces. The purpose of this study was to determine the effect of heel height on resultant ankle flexion moments during running. It was assumed that plantarflexion moments at the ankle joint would indicate Achilles tendon loading. Each of the five subjects performed five running trials (4.6 m.s-1) for each of the five shoes, differing only in heel height (2.1-3.3 cm). Resultant plantar-/dorsiflexion moments were calculated using a standard three-dimensional inverse dynamics analysis. The results showed that, typically, a small initial dorsiflexion moment took place changing into a larger plantarflexion moment before 20% of stance phase. The magnitude and time of occurrence of the initial dorsiflexion moment were significantly affected by heel height changes, but the maximum plantarflexion moment and its time of occurrence were not significantly affected. The results did not support the speculation that a heel lift generally decreases the Achilles tendon loading during running. However, single subject analyses indicated that for two subjects the plantarflexion moments decreased with increasing heel height.

Achilles Tendon

Energy aspects for elastic and viscous shoe soles and playing surfaces.

The purpose of this project was to determine the effect of changes in stiffness and viscosity of the foot ground interface on the work performed during locomotion. The estimation of the work during locomotion was derived from a mathematical two segment model, representing the foot and the rest of the body. The typical passive elements between the foot and the rest of the body were replaced by a strategic formulation of how a resultant force, F, representing the net effect of all the muscles between the foot and the rest of the body, has to evolve over time in a running situation. The calculations were performed under the assumption that the force F is selected so that the mechanical work performed by F is minimal. The estimations of the work required during a step cycle is generally higher for softer than for harder springs and for low damping compared with high damping. The model calculations demonstrate that specific combinations of material properties may be advantageous or disadvantageous from an energy point of view.

Algorithms

A kinematic comparison of overground and treadmill running.

Treadmills are often used in research projects to simulate overground locomotion, assuming that locomotion is similar on a treadmill and overground. The purpose of this investigation was to determine whether a treadmill could be used to simulate overground locomotion. Twenty-two subjects ran on four different surfaces: overground and three treadmills that differed in size and power. The kinematics of the right leg and foot were studied using two high-speed Locam cameras (lateral and posterior view). The subjects ran in two different shoes at four different speeds (3.0-6.0 m.s-1). The differences in the kinematics between treadmill and overground running could be divided into systematic and subject dependent components. Subjects systematically planted their feet in a flatter position on the treadmill than overground. Most of the lower extremity kinematic variables, however, showed inconsistent trends for individual subjects, depending on the individual subject's running style, running speed, and shoe/treadmill situation. The differences were substantial. It is not yet understood how the human locomotor system adapts to a particular treadmill running situation. However, it is concluded that individual assessment of running kinematics on a treadmill for shoe or shoe orthotic assessment may possibly lead to inadequate conclusions about overground running.

Adaptation, Physiological