Search results for "Motor control"

The effects of high heeled shoes on female gait: a review.

2013

Walking is the most common form of human locomotion. From a motor control perspective, human bipedalism makes the task of walking extremely complex. For parts of the step cycle, there is only one foot on the ground, so both balance and propulsion are required in order for the movement to proceed smoothly. One condition known to compound the difficulty of walking is the use of high heeled shoes, which alter the natural position of the foot–ankle complex, and thereby produce a chain reaction of (mostly negative) effects that travels up the lower limb at least as far as the spine. This review summarises recent studies that have examined acute and chronic effects of high heels on balance and lo…

Ski Boots Do Not Impair Standing Balance by Restricting Ankle-Joint Mobility.

2018

Objective: This study was undertaken in order to provide new insight into sensorimotor control of posture when wearing high-shaft (HS) boots as ski boots. Background: Previous studies into the effects of HS boots on postural control have produced controversial results. Some studies reported postural control impairments with ski boots in bipedal postural tasks due to ankle movement restrictions without quantifying the actual restrictive effect of these boots and specifying the adaptations of the postural control system. Method: Eighteen young healthy subjects took part in the experiment. Bilateral postural control was assessed on stable and unstable surfaces, while standing barefoot or weari…

Quantifying the contribution of arm postural tremor to the outcome of goal-directed pointing task by displacement measures.

2004

A method for quantifying the outcome of goal-directed postural pointing was presented and used for relating the tremor output to the oscillations of single arm landmarks. The displacement of reflective markers placed on shoulder, upper arm, forearm, and hand were measured by an optoelectronic motion capture system in nine subjects holding a laser penlight pointed at a target. The high signal-to-noise ratio of the measured displacement series (from 7:1 for shoulder marker to 30:1 for hand marker) demonstrated the feasibility of the proposed system to carry out tremor analysis. The track of the laser emission on the target, reconstructed from penlight displacements, was studied as the outcome…

Relationship between skin temperature and muscle activation during incremental cycle exercise.

2015

While different studies showed that better fitness level adds to the efficiency of the thermoregulatory system, the relationship between muscular effort and skin temperature is still unknown. Therefore, the present study assessed the relationship between neuromuscular activation and skin temperature during cycle exercise. Ten physically active participants performed an incremental workload cycling test to exhaustion while neuromuscular activations were recorded (via surface electromyography - EMG) from rectus femoris, vastus lateralis, biceps femoris and gastrocnemius medialis. Thermographic images were recorded before, immediately after and 10 min after finishing the cycling test, at four …

Modular reorganization of gait in chronic but not in artificial knee joint constraint

2021

It is currently unknown if modular reorganization does occur if not the central nervous system, but the musculoskeletal system is affected. The aims of this study were to investigate 1) the effects of an artificial knee joint constraint on the modular organization of gait in healthy subjects; and 2) the differences in modular organization between healthy subjects with an artificial knee joint constraint and people with a similar but chronic knee joint constraint. Eleven healthy subjects and eight people with a chronic knee joint constraint walked overground at 1 m/s. The healthy subjects also walked with a constraint limiting knee joint movement to 20_. The total variance accounted (tVAF) f…

Deafferentation and pointing with visual double-step perturbations

1999

The capability of reprogramming movement responses following changes in the visual goal has been studied through the double-step paradigm. These studies have shown that: (a) continuous internal feedback-loops correct unconsciously the dynamic errors throughout the movement; (b) proprioceptive information and/or the efference copy have a privileged status among central processes, insuring on-line regulation of the initial motor commands; and (c) generation of the motor program starts after target presentation, and is continuously updated in the direction of the current internal representation of the target, at least until the onset of hand movement. This main corrective process of the initia…

Changes in Postural Balance in Frail Elderly Women during a 4-Week Visual Feedback Training: A Randomized Controlled Trial

2002

<i>Background:</i> Balance training programs have not shown consistent results among older adults, and it remains unclear how different training methods can be adapted to frail elderly people. <i>Objective: </i>The purpose of this study was to investigate the effects of a 4-week visual feedback-based balance training on the postural control of frail elderly women living in residential care homes. <i>Methods:</i> Elderly women of two residential care facilities were randomized to an exercise group (EG, n = 20) and to a control group (CG, n = 7). The EG participated in training sessions three times/week for 4 weeks. The exercises were carried out with a com…

2020

Motor control is associated with suppression of oscillatory activity in alpha (8–12 Hz) and beta (12–30 Hz) ranges and elevation of oxygenated hemoglobin levels in motor-cortical areas. Aging leads to changes in oscillatory and hemodynamic brain activity and impairments in motor control. However, the relationship between age-related changes in motor control and brain activity is not yet fully understood. Therefore, this study aimed to investigate age-related and task-complexity-related changes in grip force control and the underlying oscillatory and hemodynamic activity. Sixteen younger [age (mean ± SD) = 25.4 ± 1.9, 20–30 years] and 16 older (age = 56.7 ± 4.7, 50–70 years) healthy men were…

Using tools effectively despite defective hand posture: A single-case study.

2019

Apraxia, a cognitive disorder of motor control, can severely impair transitive actions (object-related) and may lead to action errors (e.g., rubbing a hammer on a nail instead of pounding it) and hand posture errors (e.g., grasping a tool in a wrong way). Here, we report a rare observation of a left-handed patient, left-lateralized for language, who developed a severe apraxia following a right brain lesion. Interestingly the patient showed a significant number of hand posture errors, while she perfectly demonstrated the actual use of tools. This case stressed the predictions made by the current theories of tool use. According to the manipulation-based approach, the hand posture errors shoul…

Effects of tinnitus on postural control and stabilization: A pilot study

2015

Introduction: The aim of this study was to evaluate the tinnitus's impacts on postural control. Material and methods: Sixty-six subjects (age: 46,71 ± 15,12 years, height 166,32 ± 8,88 cm, weight 64,85 ± 12,57 kg) with idiopathic tinnitus were recruited for the study and were tested. Each subject underwent to ‘Romberg test’, ‘Static balance’ and ‘posture analysis’. Static balance and posture analysis were performed two times, with open and close eyes, and were measured through the FreeMed posturography system. Results: showed that subjects had worse Baropodometric performances respect to benchmarks; moreover according to literature the results show that these patients had significant differ…