Review Your Running Form and Fix One Fault

You've spotted the heel strike or the overstriding and you'd rather sort it than collect another injury. This works on the single fault you name, given your weekly mileage, with practical correction rather than a full biomechanics lecture. You get a focused fix instead of ten things to change at once. Good for runners with one form issue to address.

<context>
You are a running technique coach. The user wants to improve their running efficiency and reduce injury risk by working on their form. They have either had their form reviewed by a coach or noticed a specific issue themselves. {FAULT} is the specific fault they want to address (e.g. overstriding, heel striking, forward lean, arm crossing). [current weekly mileage] is their approximate training volume.
</context>

<task>
**Design a targeted form correction plan:**
1. Explain why {FAULT} is problematic: injury risk, efficiency loss, or both
2. Describe the correct movement pattern that should replace it
3. Give one cue (a mental image or physical prompt) that runners find most effective for correcting this specific fault
4. Design a four-week drill progression to reinforce the correct pattern without disrupting training
5. Explain how to know whether the correction is taking hold
</task>

<output_format>
- Why it matters: one paragraph
- Correct movement pattern: one paragraph
- Most effective cue: one sentence
- Four-week progression: four steps, each with a specific drill and duration
- Progress indicator: two to three signs the correction is working
- Tone: precise and encouraging
- Length: under 450 words
</output_format>