Loading the Limb During Rhythmic Leg Movements Lengthens the Duration of Both Flexion and Extension in Human Infants

2007 ◽  
Vol 97 (2) ◽  
pp. 1247-1257 ◽  
Author(s):  
Kristin E. Musselman ◽  
Jaynie F. Yang
Keyword(s):  
Sensory Input ◽  
Weight Bearing ◽  
Contact Forces ◽  
Cycle Period ◽  
Rhythmic Movements ◽  
Human Infants ◽  
Motor Outputs ◽  
Flexion And Extension ◽  
Leg Movements ◽  
Rule Out

Sensory input is critical for adapting motor outputs to meet environmental conditions. A ubiquitous force on all terrestrial animals is gravity. It is possible that when performing rhythmic movements, animals respond to load-related feedback in the same way by prolonging the muscle activity resisting the load. We hypothesized that for rhythmic leg movements, the period (extension or flexion) experiencing the higher load will be longer and vary more strongly with cycle period. Six rhythmic movements were studied in human infants (aged 3–10 mo), each providing different degrees of load-related feedback to the legs during flexion and extension of the limb. Kicking in supine provided similar loads (inertial) during flexion and extension. Stepping on a treadmill, kicking in supine against a foot-plate, and kicking in sitting loaded the legs during extension more than flexion, whereas air-stepping and air-stepping with ankle weights did the opposite. Video, electrogoniometry, surface electromyography, and contact forces were recorded. We showed that load-related feedback could make either the duration of flexion or extension longer. Within the tasks of stepping and kicking against a plate, infants who exerted lower forces showed shorter extensor durations than those who exerted higher forces. Because older babies tend to step with greater force, we wished to rule out the contribution of age. Eight babies (>8 mo old) were studied during stepping, in which we manipulated the amount of weight-bearing. The same effect of load was seen. Hence, the degree of loading directly affects the duration of extension in an incremental way.

Interlimb Coordination in Rhythmic Leg Movements: Spontaneous and Training-Induced Manifestations in Human Infants

2008 ◽  
Vol 100 (4) ◽  
pp. 2225-2234 ◽  
Author(s):  
Kristin E. Musselman ◽  
Jaynie F. Yang
Keyword(s):  
Weight Bearing ◽  
Neural Substrates ◽  
Interlimb Coordination ◽  
Phase Lag ◽  
Rhythmic Movements ◽  
Human Infants ◽  
Young Infants ◽  
Smooth Transitions ◽  
And Training ◽  
Leg Movements

Different rhythmic leg movements in vertebrates can share coordinating neural circuitry. These movements are often similar kinematically, and smooth transitions between the different movements are common. We focused on interlimb coordination of the legs in young infants to determine whether weight bearing and non–weight bearing movements might share coordinating circuitry. If interlimb coordination is controlled by the same circuitry, the same coordination (i.e., either synchronous or alternate) should be seen in different rhythmic movements. Moreover, if we altered the interlimb coordination in one movement through exercise, it should translate to a change in coordination in another rhythmic movement that received no exercise. Video and electrogoniometry were recorded while 46 infants (age, 6.2 ± 1.4 mo) performed non–weight bearing and weight bearing movements. Interlimb coordination was quantified by the phase lag between the movement cycles of each leg. Most infants (83%) showed the same coordination in weight bearing and non–weight bearing movements. Ten infants practiced the form of coordination they did not exhibit in the first visit, in weight bearing for 4 wk. Following practice, 8 of 10 infants changed their interlimb coordination in weight bearing to that practiced. Some who practiced synchronous coordination also changed their coordination in non–weight bearing activity. More infants showed both forms of coordination after practice and smooth transitions between the two forms. The results suggest that interlimb coordination is malleable in infants, and there is a partial sharing of the neural substrates for interlimb coordination between different rhythmic leg movements in infants.

Discharge Patterns of Coxal Levator and Depressor Motoneurones of the Cockroach, Periplaneta Americana

1970 ◽  
Vol 52 (1) ◽  
pp. 139-165
Author(s):  
K. G. PEARSON ◽  
J. F. ILES
Keyword(s):  
Peripheral Nerves ◽  
Sensory Input ◽  
Periplaneta Americana ◽  
Motor Axon ◽  
Extracellular Recordings ◽  
Before And After ◽  
Collateral Pathways ◽  
Discharge Patterns ◽  
Flexion And Extension ◽  
Leg Movements

1. Observation of movements of the metathoracic legs of the cockroach before and after section of peripheral nerves allowed identification of muscles involved in flexion and extension of the femur. 2. Extracellular recordings from the nerves to these coxal muscles show that during rhythmic leg movements bursts of activity in a number of levator motor axons were strongly reciprocal and generally non-overlapping with those of a slow depressor motor axon. 3. These reciprocal patterns persisted after removal of all sensory input from the legs. 4. The durations of levator bursts were relatively constant compared to those of the depressor, corresponding to the behavioural observations on leg protraction time. The pattern was asymmetric: levator bursts could be generated without depressor activity, but never the reverse. 5. No evidence was found for inhibitory collateral pathways between antagonist motoneurones. 6. It is proposed that levator motoneurones are driven by a group of bursting interneurones which simultaneously inhibit the ongoing depressor activity.

Tonic Central and Sensory Stimuli Facilitate Involuntary Air-Stepping in Humans

2009 ◽  
Vol 101 (6) ◽  
pp. 2847-2858 ◽  
Author(s):  
V. A. Selionov ◽  
Y. P. Ivanenko ◽  
I. A. Solopova ◽  
V. S. Gurfinkel
Keyword(s):  
Ankle Joint ◽  
Sensory Input ◽  
Contact Forces ◽  
Muscle Vibration ◽  
Sensory Stimuli ◽  
Healthy Humans ◽  
S Period ◽  
Static Conditions ◽  
Jendrassik Maneuver ◽  
Leg Movements

Air-stepping can be used as a model for investigating rhythmogenesis and its interaction with sensory input. Here we show that it is possible to entrain involuntary rhythmic movement patterns in healthy humans by using different kinds of stimulation techniques. The subjects lay on their sides with one or both legs suspended, allowing low-friction horizontal rotation of the limb joints. To evoke involuntary stepping of the suspended leg, either we used continuous muscle vibration, electrical stimulation of the superficial peroneal or sural nerves, the Jendrassik maneuver, or we exploited the postcontraction state of neuronal networks (Kohnstamm phenomenon). The common feature across all stimulations was that they were tonic. Air-stepping could be elicited by most techniques in about 50% of subjects and involved prominent movements at the hip and the knee joint (∼40–70°). Typically, however, the ankle joint was not involved. Minimal loading forces (4–25 N) applied constantly to the sole (using a long elastic cord) induced noticeable (∼5–20°) ankle-joint-angle movements. The aftereffect of a voluntary long-lasting (30-s) contraction in the leg muscles featured alternating rhythmic leg movements that lasted for about 20–40 s, corresponding roughly to a typical duration of the postcontraction activity in static conditions. The Jendrassik maneuver per se did not evoke air-stepping. Nevertheless, it significantly prolonged rhythmic leg movements initiated manually by an experimenter or by a short (5-s) period of muscle vibration. Air-stepping of one leg could be evoked in both forward and backward directions with frequent spontaneous transitions, whereas involuntary alternating two-legged movements were more stable (no transitions). The hypothetical role of tonic influences, contact forces, and bilateral coordination in rhythmogenesis is discussed. The results overall demonstrated that nonspecific tonic drive may cause air-stepping and the characteristics and stability of the evoked pattern depended on the sensory input.

Locomotory behavior in the hawkmoth Manduca sexta: kinematic and electromyographic analyses of the thoracic legs in larvae and adults.

1996 ◽  
Vol 199 (4) ◽  
pp. 759-774 ◽  
Author(s):  
R M Johnston ◽  
R B Levine
Keyword(s):  
Manduca Sexta ◽  
Motor Neurons ◽  
Muscle Activity ◽  
Weight Bearing ◽  
Strong Dependence ◽  
Sensory Information ◽  
Cycle Period ◽  
Electromyographic Activity ◽  
Thoracic Legs ◽  
Leg Movements

During metamorphosis in Manduca sexta, muscles and most sensory structures of the thoracic legs undergo extensive changes while the motor neurons that are present in the larva persist into the adult. The main goal of this work was to identify similarities and dissimilarities in thoracic leg movements during crawling in larvae and walking in adults. This information provides a foundation for understanding the extent to which centrally located neural elements are reorganized during metamorphosis to accommodate changes in locomotion. Analysis of electromyographic activity from leg muscles synchronized with video-taped recordings of the leg movements during larval crawling and adult walking revealed differences in cycle periods as well as intersegmental and intrasegmental patterns of coordination. Larval crawling was characterized by synchronous movements of segmental pairs of legs as activity proceeded slowly from the move posterior to the more anterior segments. During crawling, antagonistic muscles maintained a strict reciprocity. In contrast, walking in adults was characterized by fast, alternating movements of the left and right prothoracic legs and more variable coordination patterns in the mesothoracic and metathoracic legs (ranging from synchrony to alternation). In adults, sensory information, possibly associated with the weight-bearing or postural demands of walking on an incline, contributed to a strong dependence between the duration of muscle activity and cycle period and to the extent that the muscle activity overlapped during walking.

Physiology and Morphology of Shared and Specialized Spinal Interneurons for Locomotion and Scratching

2008 ◽  
Vol 99 (6) ◽  
pp. 2887-2901 ◽  
Author(s):  
Ari Berkowitz
Keyword(s):  
Direct Evidence ◽  
Ventral Horn ◽  
Morphological Properties ◽  
Rhythmic Movements ◽  
Potential Oscillations ◽  
Spinal Interneurons ◽  
Firing Rates ◽  
Motor Outputs ◽  
Membrane Potential Oscillations

Distinct types of rhythmic movements that use the same muscles are typically generated largely by shared multifunctional neurons in invertebrates, but less is known for vertebrates. Evidence suggests that locomotion and scratching are produced partly by shared spinal cord interneuronal circuity, although direct evidence with intracellular recording has been lacking. Here, spinal interneurons were recorded intracellularly during fictive swimming and fictive scratching in vivo and filled with Neurobiotin. Some interneurons that were rhythmically activated during both swimming and scratching had axon terminal arborizations in the ventral horn of the hindlimb enlargement, indicating their likely contribution to hindlimb motor outputs during both behaviors. We previously described a morphological group of spinal interneurons (“transverse interneurons” or T neurons) that were rhythmically activated during all forms of fictive scratching at higher peak firing rates and with larger membrane potential oscillations than scratch-activated spinal interneurons with different dendritic orientations. The current study demonstrates that T neurons are activated during both swimming and scratching and thus are components of the shared circuitry. Many spinal interneurons activated during fictive scratching are also activated during fictive swimming (scratch/swim neurons), but others are suppressed during swimming (scratch-specialized neurons). The current study demonstrates that some scratch-specialized neurons receive strong and long-lasting hyperpolarizing inhibition during fictive swimming and are also morphologically distinct from T neurons. Thus this study indicates that locomotion and scratching are produced by a combination of shared and dedicated interneurons whose physiological and morphological properties are beginning to be revealed.

In Vivo Tibiofemoral Contact Kinematics and Contact Forces During Dynamic Weight-Bearing Activities Following Total Knee Arthroplasty

2008 ◽  
Author(s):  
Kartik M. Varadarajan ◽  
Angela Moynihan ◽  
Darryl D’Lima ◽  
Clifford W. Colwell ◽  
Harry E. Rubash ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Computational Models ◽  
Imaging System ◽  
Weight Bearing ◽  
Contact Forces ◽  
Inverse Dynamic ◽  
Contact Kinematics ◽  
Total Knee

Accurate knowledge of in vivo articular contact kinematics and contact forces is required to quantitatively understand factors limiting life of total knee arthroplasty (TKA) implants, such as polyethylene component wear and implant loosening [1]. Determination of in vivo tibiofemoral contact forces has been a challenging issue in biomechanics. Historically, instrumented tibial implants have been used to measure tibiofemoral forces in vitro [2] and computational models involving inverse dynamic optimization have been used to estimate joint forces in vivo [3]. Recently, D’Lima et al. reported the first in vivo measurement of 6DOF tibiofemoral forces via an instrumented implant in a TKA patient [4]. However this technique does not provide a direct estimation of tibiofemoral contact forces in the medial and lateral compartments. Recently, a dual fluoroscopic imaging system has been used to accurately determine tibiofemoral contact locations on the medial and lateral tibial polyethylene surfaces [5]. The objective of this study was to combine the dual fluoroscope technique and the instrumented TKAs to determine the dynamic 3D articular contact kinematics and contact forces on the medial and lateral tibial polyethylene surfaces during functional activities.

Gating of Afferent Input by a Central Pattern Generator

1999 ◽  
Vol 81 (2) ◽  
pp. 950-953 ◽  
Author(s):  
Ralph A. DiCaprio
Keyword(s):  
Central Pattern Generator ◽  
Sensory Input ◽  
Motor Pattern ◽  
Pattern Generator ◽  
Afferent Input ◽  
Inhibitory Input ◽  
Cycle Period ◽  
Intracellular Recordings ◽  
Afferent Fibers ◽  
Sufficient Magnitude

Gating of afferent input by a central pattern generator. Intracellular recordings from the sole proprioceptor (the oval organ) in the crab ventilatory system show that the nonspiking afferent fibers from this organ receive a cyclic hyperpolarizing inhibition in phase with the ventilatory motor pattern. Although depolarizing and hyperpolarizing current pulses injected into a single afferent will reset the ventilatory motor pattern, the inhibitory input is of sufficient magnitude to block afferent input to the ventilatory central pattern generator (CPG) for ∼50% of the cycle period. It is proposed that this inhibitory input serves to gate sensory input to the ventilatory CPG to provide an unambiguous input to the ventilatory CPG.

Neuronal control of walking: studies on insects

e-Neuroforum ◽  
2015 ◽  
Vol 21 (4) ◽  
Author(s):  
Ansgar Büschges ◽  
Joachim Schmidt
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sensory Input ◽  
Central Pattern Generators ◽  
Movement Direction ◽  
Coordination Pattern ◽  
Differential Processing ◽  
Neuronal Control ◽  
Pattern Generators ◽  
Leg Movements

AbstractThe control of walking in insects is to a substantial amount a function of neuronal networks in the thoracic ganglia. While descending signals from head ganglia provide general commands such as for walking direction and velocity, it is the thoracic central nervous system that controls movements of individual joints and legs. The coordination pattern of legs is velocity dependent. However, a clear stereotypic coordination pattern appears only at high velocities. In accordance with the unit burst oscillator concept, oscillatory networks (central pattern generators (CPGs)) interlocked with movement and load sensors control the timing and amplitude of joint movements. For a leg’s movements different joint CPGs of a leg are mainly coupled by proprioceptors. Differential processing of proprioceptive signals allows a task specific modulation of leg movements, for example, for changing movement direction. A switch between walking and searching movements of a leg is under local control. When stepping into a gap missing sensory input and the activation of a local command neuron evokes stereotypic searching movements of the leg.

scholarly journals In vivo contact kinematics and contact forces of the knee after total knee arthroplasty during dynamic weight-bearing activities

2008 ◽  
Vol 41 (10) ◽  
pp. 2159-2168 ◽  
Author(s):  
Kartik M. Varadarajan ◽  
Angela L. Moynihan ◽  
Darryl D’Lima ◽  
Clifford W. Colwell ◽  
Guoan Li
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Weight Bearing ◽  
Contact Forces ◽  
Dynamic Weight ◽  
Contact Kinematics ◽  
Total Knee

scholarly journals Biomechanical Study of a Tricompartmental Unloader Brace for Patellofemoral or Multicompartment Knee Osteoarthritis

2021 ◽  
Vol 8 ◽  
Author(s):  
Chris A. McGibbon ◽  
Scott Brandon ◽  
Emily L. Bishop ◽  
Chris Cowper-Smith ◽  
Edmund N. Biden
Keyword(s):  
Knee Joint ◽  
Knee Flexion ◽  
Sagittal Plane ◽  
Weight Bearing ◽  
Knee Injuries ◽  
Statistical Parameter ◽  
Quadriceps Tendon ◽  
Biomechanical Study ◽  
Contact Forces ◽  
Joint Force

Objective: Off-loader knee braces have traditionally focused on redistributing loads away from either the medial or lateral tibiofemoral (TF) compartments. In this article, we study the potential of a novel “tricompartment unloader” (TCU) knee brace intended to simultaneously unload both the patellofemoral (PF) and TF joints during knee flexion. Three different models of the TCU brace are evaluated for their potential to unload the knee joint.Methods: A sagittal plane model of the knee was used to compute PF and TF contact forces, patellar and quadriceps tendon forces, and forces in the anterior and posterior cruciate ligaments during a deep knee bend (DKB) test using motion analysis data from eight participants. Forces were computed for the observed (no brace) and simulated braced conditions. A sensitivity and validity analysis was conducted to determine the valid output range for the model, and Statistical Parameter Mapping was used to quantify the effectual region of the different TCU brace models.Results: PF and TF joint force calculations were valid between ~0 and 100 degrees of flexion. All three simulated brace models significantly (p < 0.001) reduced predicted knee joint loads (by 30–50%) across all structures, at knee flexion angles >~30 degrees during DKB.Conclusions: The TCU brace is predicted to reduce PF and TF knee joint contact loads during weight-bearing activity requiring knee flexion angles between 30 and 100 degrees; this effect may be clinically beneficial for pain reduction or rehabilitation from common knee injuries or joint disorders. Future work is needed to assess the range of possible clinical and prophylactic benefits of the TCU brace.

Sign in / Sign up

Export Citation Format

Share Document