49 research outputs found
MSJ845839_supplemental_material – Supplemental material for Repeated assessment of key clinical walking measures can induce confounding practice effects
No full textSupplemental material, MSJ845839_supplemental_material for Repeated assessment of key clinical walking measures can induce confounding practice effects by Christian Meyer, Tim Killeen, Lilla Lörincz, Armin Curt, Marc Bolliger, Michael Linnebank, Björn Zörner and Linard Filli in Multiple Sclerosis Journal</p
Structural and functional reorganization of propriospinal connections promotes functional recovery after spinal cord injury
No full textAxonal regeneration and fiber regrowth is limited in the adult central nervous system, but research over the last decades has revealed a high intrinsic capacity of brain and spinal cord circuits to adapt and reorganize after smaller injuries or denervation. Short-distance fiber growth and synaptic rewiring was found in cortex, brain stem and spinal cord and could be associated with restoration of sensorimotor functions that were impaired by the injury. Such processes of structural plasticity were initially observed in the corticospinal system following spinal cord injury or stroke, but recent studies showed an equally high potential for structural and functional reorganization in reticulospinal, rubrospinal or propriospinal projections. Here we review the lesion-induced plastic changes in the propriospinal pathways, and we argue that they represent a key mechanism triggering sensorimotor recovery upon incomplete spinal cord injury. The formation or strengthening of spinal detour pathways bypassing supraspinal commands around the lesion site to the denervated spinal cord were identified as prominent neural substrate inducing substantial motor recovery in different species from mice to primates. Indications for the existence of propriospinal bypasses were also found in humans after cortical stroke. It is mandatory for current research to dissect the biological mechanisms underlying spinal circuit remodeling and to investigate how these processes can be stimulated in an optimal way by therapeutic interventions (e.g., fiber-growth enhancing interventions, rehabilitation). This knowledge will clear the way for the development of novel strategies targeting the remarkable plastic potential of propriospinal circuits to maximize functional recovery after spinal cord injury
Elektrische Stimulation des Rückenmarks zur Behandlung von Gangstörungen bei Querschnittlähmung
No full textMotor physiology and neural network anatomy in rats following incomplete cervical spinal cord injury
No full textReticulospinal modulation of muscle activation and electromechanical coupling: evidence from the StartReact paradigm
No full textIntroductionMovement initiation relies on descending motor drive conveying motor commands from the brain to spinal motor circuits, leading to the activation of specific muscles to produce the intended movement. While the role of descending motor drive on the onset of muscle activation has been extensively examined, its impact on motor unit recruitment, muscle fiber activation, and the electromechanical delay (EMD) remain poorly understood. This study aimed to elucidate the role of the reticulospinal (RS) system in shaping muscle activation patterns, movement initiation, and the EMD by employing the StartReact paradigm.MethodsThe StartReact paradigm was implemented in 29 healthy participants performing 14 single-joint motor tasks including both upper and lower extremities. Muscle activity was recorded using surface electromyography (EMG), while movement patterns were acquired via motion capture technology. Muscle activation and movement patterns were analyzed in both temporal and amplitude domains to characterize differences between movements cued by either loud (LAS: 120 dB) or moderate acoustic stimuli (MAS: 82 dB). EMD was defined as the time interval between EMG onset and movement initiation.ResultsOur results revealed faster and more pronounced muscle activation and movement performance in response to LAS compared to MAS. Notably, EMD was significantly reduced in LAS trials, suggesting that enhanced RS drive facilitates more rapid electromechanical coupling.DiscussionThese findings suggest that RS drive not only shortens muscular reaction times – characteristic of the StartReact effect - but also modulates muscle activation and movement dynamics in a way that accelerates the transition from muscle activation to movement. The observed reduction in EMD likely reflects changes in motor unit recruitment and muscle fiber activation, highlighting an additional mechanism through which the RS system enables rapid, explosive motor responses. This study provides novel insights into how descending motor drive modulates muscle activation and movement execution, and emphasizes the relevance of the RS system in supporting rapid, high-force movements essential for protective reflexes and athletic performances
Author response: Monitoring long-term efficacy of fampridine in gait-impaired patients with multiple sclerosis
No full textMotor deficits and recovery in rats with unilateral spinal cord hemisection mimic the Brown-Sequard syndrome
No full textCervical incomplete spinal cord injuries often lead to severe and persistent impairments of sensorimotor functions and are clinically the most frequent type of spinal cord injury. Understanding the motor impairments and the possible functional recovery of upper and lower extremities is of great importance. Animal models investigating motor dysfunction following cervical spinal cord injury are rare. We analysed the differential spontaneous recovery of fore- and hindlimb locomotion by detailed kinematic analysis in adult rats with unilateral C4/C5 hemisection, a lesion that leads to the Brown-Séquard syndrome in humans. The results showed disproportionately better performance of hindlimb compared with forelimb locomotion; hindlimb locomotion showed substantial recovery, whereas the ipsilesional forelimb remained in a very poor functional state. Such a differential motor recovery pattern is also known to occur in monkeys and in humans after similar spinal cord lesions. On the lesioned side, cortico-, rubro-, vestibulo- and reticulospinal tracts and the important modulatory serotonergic, dopaminergic and noradrenergic fibre systems were interrupted by the lesion. In an attempt to facilitate locomotion, different monoaminergic agonists were injected intrathecally. Injections of specific serotonergic and noradrenergic agonists in the chronic phase after the spinal cord lesion revealed remarkable, although mostly functionally negative, modulations of particular parameters of hindlimb locomotion. In contrast, forelimb locomotion was mostly unresponsive to these agonists. These results, therefore, show fundamental differences between fore- and hindlimb spinal motor circuitries and their functional dependence on remaining descending inputs and exogenous spinal excitation. Understanding these differences may help to develop future therapeutic strategies to improve upper and lower limb function in patients with incomplete cervical spinal cord injuries
Motor deficits and recovery in rats with unilateral spinal cord hemisection mimic the Brown-Séquard syndrome
No full textCervical incomplete spinal cord injuries often lead to severe and persistent impairments of sensorimotor functions and are clinically the most frequent type of spinal cord injury. Understanding the motor impairments and the possible functional recovery of upper and lower extremities is of great importance. Animal models investigating motor dysfunction following cervical spinal cord injury are rare. We analysed the differential spontaneous recovery of fore- and hindlimb locomotion by detailed kinematic analysis in adult rats with unilateral C4/C5 hemisection, a lesion that leads to the Brown-Séquard syndrome in humans. The results showed disproportionately better performance of hindlimb compared with forelimb locomotion; hindlimb locomotion showed substantial recovery, whereas the ipsilesional forelimb remained in a very poor functional state. Such a differential motor recovery pattern is also known to occur in monkeys and in humans after similar spinal cord lesions. On the lesioned side, cortico-, rubro-, vestibulo- and reticulospinal tracts and the important modulatory serotonergic, dopaminergic and noradrenergic fibre systems were interrupted by the lesion. In an attempt to facilitate locomotion, different monoaminergic agonists were injected intrathecally. Injections of specific serotonergic and noradrenergic agonists in the chronic phase after the spinal cord lesion revealed remarkable, although mostly functionally negative, modulations of particular parameters of hindlimb locomotion. In contrast, forelimb locomotion was mostly unresponsive to these agonists. These results, therefore, show fundamental differences between fore- and hindlimb spinal motor circuitries and their functional dependence on remaining descending inputs and exogenous spinal excitation. Understanding these differences may help to develop future therapeutic strategies to improve upper and lower limb function in patients with incomplete cervical spinal cord injurie
PENGEMBANGAN MODEL LATIHAN TEKNIK MENGGIRING DAN MENGOPERDALAM SEPAKBOLA (Studi Pengembangan pada Atlet Usia 11- 12 Tahun di Kota Medan)
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ABSTRACT
The background of research was that dribbling and passing technique
practice during practicing was less varied, and the level of dribbling and passing
technique mastery was still low in athlete aged 11-12 years in Medan City. The
objectives of research were to conduct and to find out the result of requirement
analysis and to develop preliminary product, to conduct and to find out expert and
field tests, and to conduct and to find out the effectiveness test of dribbling and
passing practice model product in soccer among the athletes aged 11-12 years in
Medan City.
The research method used was Research Development one suggested by
Borg and Gall, the author adapted the research procedure into three stages: (1)
preliminary, (2) product trial, and (3) product effectiveness test.
The first result, preliminary, was the requirement analysis using interview
and observation method indicated that the dribbling and passing technique
practice during practicing was less varied, and the level of dribbling and passing
technique mastery was still low in athlete aged 11-12 years in Medan City.
Dribbling and passing practices had been administered but many athletes
particularly those aged 11-12 years had not been able to do them well. The
theoretical study consisted of soccer, the theories of dribbling and passing
technique, of physical condition to dribble and to pass, of 11-12 years
characteristics, and of practicing. This research was presented as follows: chapter
I introduction, chapter II practice to dribble and to pass, chapter III dribbling and
passing practice model and chapter IV practice program. The second stage was
product trial. The first trial was expert trial employing three soccer expert with 18
items of question with 80% result and it could be interpreted that the product
design could be developed further. The small group trial was conducted with 24
subjects using questionnaire containing 12 items. The result of small group test
was 72.70%, the large group trial was conducted with 48 subjects with the result
of 84.79%. The third stage was product effectiveness test by comparing two
groups: one was given development product treatment and another was given
conventional treatment using pre-test and post-test design. The variance score for
each group based on the test was the sum of variance score in test 1 was 69.33 for
experiment and 68.51 for control groups. The variance score in test 2 was 100 for
experiment and 73 for control groups. The variance score in test 3 was 55 for
experiment and 35 for control groups. The variance score in test 4 was 58 for
experiment and 35 for control groups. The conclusion was that the product was
evidently effective to improve the dribbling and passing ability among the athletes
aged 11-12 years in Medan City.
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Latar belakang penelitian adalahlatihan teknik menggiring dan mengoper
pada saat latihan kurang bervariasi, dan masih rendahnya tingkat penguasaan
teknik menggiring dan mengoper pada atlet usia 11-12 tahun di kota Medan.
Tujuan penelitian adalah melaksanakan dan mengetahui hasil analisis kebutuhan
dan mengembangkan produk awal, melaksanakan dan mengetahui uji ahli dan uji
lapangan, dan melaksanakan dan mengetahui uji efektivitas produk model latihan
menggiring dan mengoper dalam sepakbola pada atlet usia 11-12 tahun di kota
Medan.
Metode penelitian yang digunakan adalah metode penelitian
pengembangan Research and Development yang dikemukakan oleh Borg dan
Gall, peneliti mengadaptasi prosedur penelitian menjadi tiga tahap yaitu: tahap 1
pendahuluan, tahap 2 uji coba produk, dan tahap 3 uji efektivitas produk.
Hasil yang pertama pendahuluan adalah analisis kebutuhan dengan
menggunakan metode wawancara dan observasi Latihan teknik menggiring dan
mengoper pada saat latihan kurang bervariasi, dan masih rendahnya tingkat
penguasaan teknik menggiring dan mengoper pada atlet usia 11-12 tahun di kota
Medan. Latihan menggiringdan mengoper sudah diberikan namun masih banyak
atlet khususnya tim usia 11- 12 tahun belum bisa melakukan teknik menggiring
dan mengoperdengan baik. Kajian teori terdiri dari sepakbola, teori tentang teknik
menggiring dan mengoper, teori kondisi fisik untuk menggiring dan mengoper,
teori karakteristik usia 11-12 tahun, teori latihan. Pengembangan produk
penyajiannya yaitu bab I pendahuluan, bab II Latihan untuk menggiring dan
mengoper, bab III model latihan mengiring dan mengoper dan bab IV program
latihan. Tahap kedua adalah uji coba produk. Uji coba yang pertama adalah uji
coba ahli dengan menggunakan tiga ahli sepakbola dengan 18 butir pertanyaan
dengan hasil 80 % dan dapat diinterpretasikan bahwa rancangan produk bisa diuji
cobakan pada tahap selanjutnya. Uji coba kelompok kecil dengan jumlah subjek
24 menggunakan instrumen angket dengan jumlah pertanyaan 12.Hasil uji
kelompok kecil adalah 72.70%.uji coba kelompok besar dengan 48 subjek dengan
hasil 84.79%. Tahap yang ketiga adalah uji efektivitas produk dengan
membandingkan dua kelompok, satu kelompok diberi perlakuan produk
pengembangan dan kelompok lain diberi perlakuan secara konfensional dengan
penggunakan pre test dan post test desain. Nilai beda untuk masing-masing
kelompok berdasarkan tes adalah: Jumlah nilai beda tes 1 kelompok eksperimen
69,33, kelompok kontrol 68,51. Nilai beda tes 2 kelompok eksperimen 100,
kelompok kontrol 73. Jumlah nilai beda tes 3 kelompok eksperimen 55, kelompok
kontrol 35. Jumlah nilai beda tes 4 kelompok eksperimen 58, kelompok kontrol
35. Sebagai simpulan akhir dinyatakan bahwa produk terbukti efektif meningkatkan kemampuan menggiring dan mengoper atlet sepakbola usia 11-12
tahun di kota Medan.
Kata kunci: Sepakbola, Model Latihan menggiring dan mengoper, Penelitian
Pengembangan
