A Role for Hip Position in Initiating the Swing-to-Stance Transition in Walking Cats

2005 ◽  
Vol 94 (5) ◽  
pp. 3497-3508 ◽  
Author(s):  
D. A. McVea ◽  
J. M. Donelan ◽  
A. Tachibana ◽  
K. G. Pearson
Keyword(s):  
Hip Joint ◽  
Direct Evidence ◽  
Swing Phase ◽  
Strongly Correlated ◽  
Flexor Muscle ◽  
Extensor Muscles ◽  
Ankle Joints ◽  
Hip Flexion ◽  
Hip Flexor ◽  
Decerebrate Cats

In this investigation, we obtained data that support the hypothesis that afferent signals associated with hip flexion play a role in initiating the swing-to-stance transition of the hind legs in walking cats. Direct evidence came from observations in walking decerebrate cats. Assisting the flexion of the hip joint during swing advanced the onset of activity in ankle extensor muscles, and this advance was strongly correlated with a reduction in the duration of hip flexor muscle activity. The hip angle at the time of onset of the flexion to extension transition was similar during assisted and unassisted steps. Additional evidence for the hypothesis that sensory signals related to hip flexion are important in regulating the swing-to-stance transition came from four normal animals trained to walk in a variety of situations designed to alter the coordination of movements at the hip, knee, and ankle joints during the swing phase. Although there were exceptions in some tasks and preparations, the angle of the hip joint at the time of onset of extensor activity was generally less variable than that of the knee and ankle joints. We also found no clear relationships between the angle of the limb and body axes, or the length of the limb axis, and the time of onset of extensor activity. Finally, there were no indications that the stretching of ankle extensor muscles during swing was a factor in regulating the transition from swing-to-stance.

Proprioceptive Modulation of Hip Flexor Activity During the Swing Phase of Locomotion in Decerebrate Cats

2001 ◽  
Vol 86 (3) ◽  
pp. 1321-1332 ◽  
Author(s):  
Tania Lam ◽  
Keir G. Pearson
Keyword(s):  
Swing Phase ◽  
Burst Activity ◽  
Afferent Feedback ◽  
Medial Gastrocnemius ◽  
Flexor Muscle ◽  
Decerebrate Cat ◽  
Leg Extension ◽  
Flexor Muscles ◽  
Hip Flexion ◽  
Hip Flexor

This study examined the influence of proprioceptive input from hip flexor muscles on the activity in hip flexors during the swing phase of walking in the decerebrate cat. One hindlimb was partially denervated to remove cutaneous input and afferent input from most other hindlimb muscles. Perturbations to hip movement were applied either by 1) manual resistance or assistance to swing or by 2) resistance to hip flexion using a device that blocked hip flexion but allowed leg extension. Electromyographic recordings were made from the iliopsoas (IP), sartorius, and medial gastrocnemius muscles. When the hip was manually assisted into flexion, there was a reduction in hip flexor burst activity. Conversely, when hip flexion was manually resisted or mechanically blocked during swing, the duration and amplitude of hip flexor activity was increased. We also found some specificity in the role of afferents from individual hip flexor muscles in the modulation of flexor burst activity. If the IP muscle was detached from its insertion, little change in the response to blocking flexion was observed. Specific activation of IP afferent fibers by stretching the muscle also did not greatly affect flexor activity. On the other hand, if conduction in the sartorius nerves was blocked, there was a diminished response to blocking hip flexion. The increase in duration of the flexor bursts still occurred, but this increase was consistently lower than that observed when the sartorius nerves were intact. From these results we propose that during swing, feedback from hip flexor muscle afferents, particularly those from the sartorius muscles, enhances flexor activity. In addition, if we delayed the onset of flexor activity in the contralateral hindlimb, blocking hip flexion often resulted in the prolongation of ipsilateral flexor activity for long periods of time, further revealing the reinforcing effects of flexor afferent feedback on flexor activity. This effect was not seen if conduction in the sartorius nerves was blocked. In conclusion, we have found that hip flexor activity during locomotion can be strongly modulated by modifying proprioceptive feedback from the hip flexor muscles.

scholarly journals The functional use of the reciprocal hip mechanism during gait for paraplegic patients walking in the Louisiana State University reciprocating gait orthosis

1999 ◽  
Vol 23 (2) ◽  
pp. 152-162 ◽  
Author(s):  
P. M. Dall ◽  
B. Müller ◽  
I. Stallard ◽  
J. Edwards ◽  
M. H. Granat
Keyword(s):  
Hip Joint ◽  
Swing Phase ◽  
Spinal Injuries ◽  
Small Contribution ◽  
State University ◽  
Hip Joints ◽  
Cable Tension ◽  
Louisiana State University ◽  
Hip Flexion ◽  
Limb Flexion

Reciprocally linked orthoses used for paraplegic walking have some form of linkage between the two hip joints. It has been assumed that flexion of the swinging leg is driven by extension of the stance leg. The aims of this study were to investigate the moments generated around the hip joint by the two cables in a Louisiana State University Reciprocating Gait Orthosis (LSU-RGO). Six (6) subjects were recruited from the Regional Spinal Injuries Centre at Southport, who were experienced RGO users. The cables were fitted with strain gauged transducers to measure cable tension. Foot switches were used to divide the gait into swing and stance phases. A minimum of 20 steps were analysed for each subject. Moments about the hip joint for each phase of gait were calculated. There were no moments generated by the front cable in 4 of the subjects. In only 2 subjects did the cable generate a moment that could assist hip flexion during the swing phase. These moments were very low and at best could only have made a small contribution to limb flexion. The back cable generated moments that clearly prevented bilateral flexion. It was concluded that the front cable, as used by these experienced RGO users, did not aid flexion of the swinging limb.

scholarly journals A new walking orthosis for paraplegics: hip and ankle linkage system

2004 ◽  
Vol 28 (1) ◽  
pp. 69-74 ◽  
Author(s):  
E. Genda ◽  
K. Oota ◽  
Y. Suzuki ◽  
K. Koyama ◽  
T. Kasahara
Keyword(s):  
Hip Joint ◽  
Normal Level ◽  
Step Length ◽  
The Other ◽  
Pelvic Rotation ◽  
Ankle Joints ◽  
Two Factors ◽  
Hip Flexion ◽  
Lofstrand Crutches ◽  
Foot Orthotic

For paraplegics, two major disadvantages of hip-knee-ankle-foot orthotic systems that have a medial single hip joint are the short stride and horizontal rotation of the pelvis. The authors consider the pelvic rotation is caused by two factors; one is the lack of a mechanism to assist hip flexion, and the other is fixed ankle joints that cause instability when the step length becomes longer. Users must rotate their pelvis to initiate a swing in their legs and to achieve stability by making their two legs as parallel as possible in order to avoid losing balance. To overcome those disadvantages, the authors developed a new orthosis named “HALO” (Hip and Ankle Linked Orthosis), which has a linking mechanism that connects both ankle joints with a medial single hip joint. This new orthosis allows users to keep both feet always parallel to the floor while walking, and assists the swinging of the leg when the contralateral ankle is flexed dorsally by loading. Gait analysis revealed that the pelvic rotation with “HALO” either in parallel bars or with Lofstrand crutches was within 20°, which was within the physiologically normal level.

Association of affected lower limb flexor muscle strength with swing phase duration and gait speed in elderly post-stroke patients

2020 ◽  
Vol 47 (4) ◽  
pp. 443-450
Author(s):  
Emad Moftah ◽  
Vishal Vennu ◽  
Tariq A. Abdulrahman ◽  
Ali H. Alnahdi ◽  
Hashim Balubaid ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Gait Speed ◽  
The Elderly ◽  
Swing Phase ◽  
Flexor Muscle ◽  
Stroke Patients ◽  
Phase Duration ◽  
Post Stroke ◽  
Hip Flexor ◽  
Ankle Dorsiflexor

BACKGROUND: Although several studies have shown an association of muscle weakness with gait speed (GS), no study has explored the relationship of muscle strength with swing phase duration and GS after stroke among the elderly in Saudi Arabia. OBJECTIVE: To examine the association of affected ankle dorsiflexor and hip flexor muscle strength with swing phase duration and GS in the elderly with different stroke chronicity. METHODS: In this cross-sectional study, we included a total of 60 post-stroke patients aged ≥55 years who were admitted in neurorehabilitation units between May 2017 and August 2018. Linear regression was employed to examine the association of muscle strength (measured using a handheld dynamometer) with swing phase duration and GS (both measured using the computerized Zebris–Mat). RESULTS: The chronicity of the stroke was negatively associated (p < 0.05) with swing phase duration. The ankle dorsiflexor muscle strength was significantly associated with GS (β= 0.656, p = 0.041). In contrast, hip flexor muscle strength was significantly associated with GS (β= 0.574, p < 0.0001) even after adjusting for stroke chronicity (β= 0.561, p < 0.0001). CONCLUSIONS: Stroke chronicity was the predictor that reduced swing phase duration. The ankle dorsiflexor muscle strength was associated with GS. However, the hip flexor muscle strength was associated with GS even after adjusting for stroke chronicity.

How Do Infants Adapt to Loading of the Limb During the Swing Phase of Stepping?

2003 ◽  
Vol 89 (4) ◽  
pp. 1920-1928 ◽  
Author(s):  
Tania Lam ◽  
Claire Wolstenholme ◽  
Jaynie F. Yang
Keyword(s):  
Sensory Input ◽  
Sagittal Plane ◽  
Sudden Change ◽  
Flexor Muscle ◽  
Human Infants ◽  
After Effects ◽  
After Effect ◽  
Leg Motion ◽  
Hip Flexion ◽  
Hip Flexor

Previous results from this laboratory have shown that human infants (<12 mo old) respond appropriately to transient changes in sensory input during stepping. We examined how infants adapted to a more enduring change in sensory input by applying load to one limb during stepping. A small weight (500–900 g) was strapped around the lower leg of infants aged 3–11 mo. Stepping with the weight on was recorded on the treadmill for a period of 0.5–3 min. The weight was then quickly detached during stepping, and the immediate response to unexpected loss of the weight recorded. Three-segment dynamic analysis of leg motion was used to estimate hip, knee, and ankle torques during swing in the sagittal plane. All infants adapted to the additional load on the leg by immediately increasing the generation of hip and knee flexor muscle torques. When the weight was removed, 7 of the 22 infants tested exhibited an after-effect (high stepping) in the first step after removal of the weight. The after-effect was manifested as an increase in toe trajectory height and hip flexion and coincided with higher hip flexor muscle torque in early swing. In an additional series of control experiments using seven infants, after-effects were shown to be unrelated to a sudden change in cutaneous input with removal of the weight. The presence of an after-effect indicates that some infants made an enduring adaptation to their stepping pattern that is revealed with the unexpected removal of the weight.

Abdominal and hip flexor muscle activation during various training exercises

1997 ◽  
Vol 75 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Eva A. Andersson ◽  
Johnny Nilsson ◽  
Zhijia Ma ◽  
Alf Thorstensson
Keyword(s):  
Muscle Activation ◽  
Flexor Muscle ◽  
Training Exercises ◽  
Hip Flexor

The locust jump. I. The motor programme

1977 ◽  
Vol 66 (1) ◽  
pp. 203-219
Author(s):  
W. J. Heitler ◽  
M. Burrows
Keyword(s):  
High Frequency ◽  
Tactile Stimulation ◽  
The Body ◽  
Flexor Muscle ◽  
Tactile Stimuli ◽  
Extensor Muscles ◽  
Trigger Activity ◽  
Three Stages ◽  
Motor Programme ◽  
Made In

A motor programme is described for defensive kicking in the locust which is also probably the programme for jumping. The method of analysis has been to make intracellular recordings from the somata of identified motornuerones which control the metathoracic tibiae while defensive kicks are made in response to tactile stimuli. Three stages are recognized in the programme. (1) Initial flexion of the tibiae results from the low spike threshold of tibial flexor motorneurones to tactile stimulation of the body. (2) Co-contraction of flexor and extensor muscles followa in which flexor and extensor excitor motoneurones spike at high frequency for 300-600 ms. the tibia flexed while the extensor muscle develops tension isometrically to the level required for a kick or jump. (3) Trigger activity terminates the co-contraction by inhibiting the flexor excitor motorneurones and simultaneously exciting the flexor inhibitors. This causes relaxation of the flexor muscle and allows the tibiae to extend. If the trigger activity does not occur, the jump or kick is aborted, and the tibiae remain flexed.

scholarly journals Hindlimb muscular activity, kinetics and kinematics of cats jumping to their maximum achievable heights

1981 ◽  
Vol 91 (1) ◽  
pp. 73-86 ◽  
Author(s):  
F. E. Zajac ◽  
M. R. Zomlefer ◽  
W. S. Levine
Keyword(s):  
Vertical Jump ◽  
Muscular Activity ◽  
Dynamic State ◽  
Extensor Muscles ◽  
Ankle Joints ◽  
Flexor Muscles ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces ◽  
Propulsion Phase

Cats were trained to jump from a force platform to their maximum achievable heights. Vertical ground reaction forces developed by individual hindlimbs showed that the propulsion phase consists of two epochs. During the initial “preparatory phase' the cat can traverse many different paths. Irrespective of the path traversed, however, the cat always attains the same position, velocity and momentum at the end of this phase. Starting from this dynamic state the cat during the subsequent “launching phase' (about 150 ms long) generates significant propulsion as its hindlimbs develop force with identical, stereotypic profiles. Cinematographic data, electromyographic data, and computed torques about the hip, knee and ankle joints indicate that during the jump proximal extensor musculature is activated before distal musculature. During terminal experiments when the hindlimb was set at positions corresponding to those in the jump, isometric torques produced by tetanic stimulation of groups of extensor and flexor muscles were compared with computed torques developed by the same cat during previous jumps. These comparisons suggest that extensor muscles of the hindlimb are fully activated during the maximal vertical jump.

A passive dynamic walking model with Coulomb friction at the hip joint

Robotica ◽  
2013 ◽  
Vol 31 (8) ◽  
pp. 1221-1227 ◽  
Author(s):  
Wenhao Guo ◽  
Tianshu Wang ◽  
Qi Wang
Keyword(s):  
Hip Joint ◽  
Coulomb Friction ◽  
Basins Of Attraction ◽  
Swing Phase ◽  
Dynamic Equations ◽  
Two Dimensional ◽  
Dynamic Walking ◽  
Passive Dynamic Walking ◽  
Impact Phase ◽  
The Impact

SUMMARYThis paper presents a modified passive dynamic walking model with hip friction. We add Coulomb friction to the hip joint of a two-dimensional straight-legged passive dynamic walker. The walking map is divided into two parts – the swing phase and the impact phase. Coulomb friction and impact make the model's dynamic equations nonlinear and non-smooth, and a numerical algorithm is given to deal with this model. We study the effects of hip friction on gait and obtain basins of attraction of different coefficients of friction.

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