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احتاج فزيو تروح لحاله فيميل بالتخصصي ، الي عنده وقت ويقدر يلتزم فضلاً يتواصل معي بالخاص واتس 0532614026

Two-Level CPG Model (More Advanced) - Addresses limitations of the one-level model by adding: - **Rhythm Generator (RG)**: Controls timing and rhythm of gait. - **Pattern Formation (PF) Network**: Regulates specific motor neuron activity. - RG and PF can independently adjust: - **Step duration** - **Gait speed** - **Motor output** - Includes input from the **mesencephalic locomotor region (MLR)**, allowing more flexible control from sensory and brain signals.

🔄 وش تستفيد أنت كفيزيو: - تقدر تطوّر بروتوكولات تأهيل تركّز على *التحفيز المتكرر* و *استخدام المدخلات الحسية* لتفعيل نمط المشي. - - وتستخدم تمارين زي الـ BWSTT (تدريب المشي مع دعم وزن الجسم) لتحفيز الـ CPG. - توظّف ردود الفعل الحسية أثناء المشي كوسيلة لفحص وتحفيز الشبكة العصبية الداخلية. ولاتنسى - عند الرُضّع، نلاحظ إنهم يبدؤون يمشون بخطوات حتى قبل ما تتكوّن المسارات الدماغية، وهذا دليل إن الحركة قد تنبع ايضاً من الحبل الشوكي 🫢

🧠 Clinical Relevance for Rehab - 🔄 Even without full brain control, **spinal networks can organize rhythm and pattern** for walking. - - 🏋️‍♀️ Training like BWSTT and reflex conditioning can stimulate CPGs. - 🧠 Using sensory input to cue specific gait phases may unlock preserved patterning, especially in neurologically impaired patients.

🧍 Evidence from Injured Adults - CPGs help generate walking patterns even after spinal cord injury. - - Studies show: - **Modulation of reflexes during gait** - **Partial weight support treadmill training** activates CPGs - **Peripheral feedback** contributes to pattern adjustment.

Central Pattern Generators (CPGs) – Simplified Breakdown 🧩 Graham Brown’s “Half-Center” Model - Each limb has its **own CPG** that controls its rhythmic movement. - Two main groups of interneurons: - **Flexor center** - **Extensor center** - These centers **inhibit each other**, so only one is active at a time. - Over time, the active center gets “fatigued” (reduced excitability), triggering a **phase switch**. - Inhibition is tightly regulated between agonists and antagonists for smooth transitions.

CPGs in Humans 🧒 Evidence from Newborns - **Newborns show stepping** patterns before their brain pathways are fully developed. 🫡 - Their gait responses are shaped by: - **Limb loading** → activates Golgi tendon organs (GTOs) - **Hip position** → activates muscle spindles - These responses are similar to spinalized animal models. 🐈

🧬 Brainstem-Spinal Integration - Brainstem and spinal cord contain networks that **coordinate timing** across muscle groups. - Modulatory systems can change the **rate of burst activity**, adapting to task demands.

ببساطة ليش اعرف هذا ^ فهم كيف يتغير المشي على الأسطح المختلفة يساعد أخصائي العلاج الطبيعي يعلّم المريض كيف يمشي بأمان، ويقلل خطر السقوط. بعدين يقدر يصمم له تمارين تناسب حياته اليومية وتساعده يتحسن أسرع. Advance Neuro Rehab 🫢

2. 🌲 Uneven Terrain (e.g., wooden planks, rocky paths) **Key Study:** Kent et al. (2019) **What Happens:** People initially walk more cautiously on uneven ground but adapt over time. **Initial Gait Modifications:** - 📈 **Increased COM variability**: More movement in the center of mass (COM). - - 📏 **Wider steps**: Increased step width for balance. - 🔻 **Shorter steps**: Reduced step length for control. **After Practice:** - 🔄 **Refined gait**: Step width decreases, step length increases. - 🧠 **Adaptation**: People become more efficient while maintaining stability. **Example:** Think of hiking on a rocky trail—at first, you walk slowly and carefully, but after a while, you find a rhythm and move more confidently.

3. 🧽 Compliant or Soft Surfaces (e.g., foam, sand) **Key Study:** Marigold & Patla (2005) **What Happens:** People adjust muscle activity and body mechanics to stay stable on soft surfaces. **Gait Modifications:** - ⚡ **Reflex response**: Muscles react within 97–175 ms to unexpected softness. - - 💪 **Increased ankle muscle activity**: Muscles like tibialis anterior and gastrocnemius stiffen to stabilize the foot. - 🔻 **Lowered COM**: Body stays closer to the ground for balance. - ↘️ **Forward trunk lean**: Helps maintain momentum and stability. - - 🦵 **More knee flexion at toe-off**: Ensures effective push-off on soft ground. **Example:** Walking on a sandy beach—you bend your knees more, lean forward slightly, and push off harder to avoid sinking or losing balance. 🫢

4. 🏃‍♂️ Running on Different Surfaces **Key Study:** Ferris et al. (1998) **What Happens:** The nervous system adjusts joint movements to maintain consistent running dynamics. **Adaptations:** - 🔁 **Joint modulation**: Adjusts joint angles and forces to keep center of mass (COM) movement and ground contact time stable. - - 🧠 **Proprioceptive feedback**: Sensors in muscles and tendons help fine-tune leg stiffness. - ❓ **Multiple mechanisms**: Even when reflexes are blocked, people maintain normal running patterns—suggesting other systems help regulate stiffness. **Example:** Running from pavement onto grass—you might not consciously notice, but your legs subtly adjust to keep your stride smooth and balanced.

Even after returning to a dry floor, people still walked cautiously, showing 5–12% lower friction values—suggesting a lingering cautious strategy. 🫡

1. 🧼 Slippery Surfaces (e.g., water, soap, oil) **Key Study:** Cham & Redfern (2002) **What Happens:** When people expect a slippery surface, they walk more cautiously to avoid slipping. **Gait Modifications:** - 🔻 **Lower required friction**: 16–33% less than normal to reduce slip risk. - - ⏱️ **Shorter stance duration**: Less time with foot on the ground. - - 🦶 **Reduced loading speed**: Slower weight transfer onto the foot. - 📏 **Shorter stride length**: Smaller steps. - - 🔄 **Slower heel strike**: -Reduced angular velocity at contact. **Example:** Imagine walking across a wet kitchen floor—you instinctively take smaller, slower steps and keep your weight more centered to avoid slipping.