D1 Flexion Pattern - Lower Limb

Joint-by-Joint Breakdown

Motion Summary

• Hip: Flexion + Adduction + External Rotation
• Knee: Flexion (in the flexion pattern)
• Ankle/Foot: Dorsiflexion with Inversion
• Toes: Extension

Starting vs. Ending Position

• Starting position: Hip extended, abducted, internally rotated; ankle plantarflexed; foot everted; toes flexed
• Ending position: Hip flexed, adducted, externally rotated; ankle dorsiflexed; foot inverted; toes extended

Muscles Primarily Activated

Clinical Application

• Used in neurological rehabilitation (stroke, cerebral palsy, spinal cord injury)
• Used in orthopedic rehab after hip, knee, or ankle surgeries
• Helps train functional diagonal movement patterns used in ADLs (activities of daily living)
• Verbal cue to patient: "Foot up, pull your knee up and in"
• Therapist hand placement:
  • One hand on the distal anterior-medial aspect of the thigh
  • Other hand on the medial aspect of the dorsal surface of the foot

Comparison with D2 Flexion

D1 Pattern Diagonal Pair

• D1 Flexion: Hip F + ADD + ER, Ankle DF + Inversion
• D1 Extension (the reverse): Hip Extension + Abduction + Internal Rotation, Ankle Plantarflexion + Eversion

PNF Lower Limb Patterns in Stroke Rehabilitation - Clinical Applications

1. Gait Improvement

• Significant improvement in gait velocity on the 10-Meter Walk Test (10MWT) (p < 0.001)
• Significant improvements in Timed Up and Go (TUG) test (p < 0.05)
• PNF outperformed conventional physiotherapy as a control condition

2. Balance Recovery

• Berg Balance Scale (BBS) (p < 0.05)
• Functional Reach Test (FRT) (p < 0.05)

3. Combined with Robotic Gait Training (2025 RCT)

• Significantly greater muscle activation (tibialis anterior, rectus femoris, core muscles) vs. RAGT alone (p < 0.05)
• Significantly greater ankle dorsiflexion angle - directly relevant to the D1 flexion endpoint
• The PNF irradiation principle means contraction of proximal muscles (hip flexors, adductors) "irradiates" activation distally to ankle dorsiflexors

4. Trunk-Targeted PNF + tDCS (2022 RCT)

• Trunk-targeted PNF + conventional PT improved gait speed, trunk control, and quality of life significantly vs. conventional PT alone
• Adding bihemispheric tDCS to PNF produced the largest gains across all outcomes

5. Specific Clinical Applications by Impairment

6. PNF Techniques Used in Stroke (paired with D1 Lower Limb)

• Rhythmic initiation - for patients with severe paresis (passive → active-assisted → active movement)
• Repeated contractions - for building endurance in weak hip flexors/adductors
• Hold-relax - for spastic ankle plantarflexors before training dorsiflexion
• Slow reversal - alternating D1 flexion and extension to improve reciprocal inhibition
• Irradiation - using upper limb or trunk patterns to "overflow" activation into the paretic lower limb

Bottom Line

1. Rhythmic Initiation (RI)

Definition

Core Goal

The 4-Stage Progression

Key Principles of RI

• Rhythm is essential - movement must be smooth and repetitive to engage motor learning circuits
• Verbal commands set the pace and rhythm: e.g., "Relax... relax... now help me... help me... push against me..."
• The speed of command volume correlates with muscle activation level - louder = more activation
• Light tracking (fingertip contact) during the active phase maintains sensory input without overpowering

Indications in Stroke

• Paresis / hemiplegia - when voluntary activation is minimal or absent
• Hypokinesia (Parkinson's-like rigidity post-stroke)
• Motor learning deficits - patient cannot sequence the movement pattern
• Aphasia - rhythm provides non-verbal cuing when verbal comprehension is impaired
• Decreased ROM - passive phase gently moves through available range before active participation begins
• Applied to D1 flexion (hip F+ADD+ER): "Let me bring your leg up and across... now help me bring it up and across... now pull your knee up and in against my hand"

2. PNF Facilitation Techniques (Overview)

The Core Facilitation Tools

A. Manual Contacts

• Therapist's grip placement on the skin directly over the muscles to be activated
• Pressure from the grip stimulates cutaneous mechanoreceptors and Golgi tendon organs
• For D1 flexion: one hand on the anteromedial thigh (targets hip flexors/adductors), other on the dorsomedial foot (targets tibialis anterior and toe extensors)
• Grip must be firm but not painful - a "lumbrical grip" (fingers and palm, not fingertips) is preferred

B. Resistance

• Applied in the opposite direction to desired movement
• Activates the stretch reflex via muscle spindles (Ia afferents)
• Promotes irradiation - overflow of neural activation from strong muscles to weak ones
• In D1 flexion, resistance to hip adduction will irradiate activation into the weaker ankle dorsiflexors

C. Traction

• Distraction/elongation of the joint space during movement
• Stimulates joint mechanoreceptors and muscle spindles
• Used during flexion patterns and movements against gravity
• Increases proprioceptive inflow and makes movement feel lighter/easier for the patient

D. Approximation

• Compression force through the joint
• Used during extension patterns, weight-bearing, and stability training
• Stimulates joint receptors to promote co-contraction and postural stability

E. Stretch

• The limb is placed in the lengthened/stretched position of the pattern before initiating movement
• This preloads the muscle spindles, eliciting a stretch reflex to initiate contraction
• For D1 flexion: starting position (hip extended, abducted, IR; ankle plantarflexed, everted) puts all target muscles on stretch
• Stretch + quick resistance = powerful facilitation of movement initiation

F. Verbal Cues

• Preparatory command: "Ready?" - alerts the patient
• Action command: "Pull your knee up and in!" - initiates movement
• Short, sharp commands increase muscle activation; softer commands promote relaxation
• Volume and timing are as important as word choice

G. Visual Input

• Patient watches the limb moving to use visual feedback to guide motor output
• Especially useful in sensory-impaired strokes where proprioception is poor

Summary: Facilitation Hierarchy in Practice

Stretch (preload) 
    → Manual contact (guide direction)
        → Verbal cue (trigger activation)
            → Resistance (build strength + irradiation)
                → Traction/Approximation (reinforce joint sense)

All PNF Techniques at a Glance (for context)