Loss of lumbar lordosis ("flat back") means your lower spine has lost its natural curve. The advice in the image is actually incorrect: strengthening glutes and hamstrings usually worsens the issue by pulling the pelvis into a posterior tilt, further flattening the back.
The Strategy

To restore the curve, you must stretch the muscles pulling the pelvis down and strengthen the muscles that arch the spine.
1. Stretch (Overactive Muscles)

Hamstrings: Tight hamstrings are the primary culprit for pulling the tailbone under.

Glutes: Deep stretches like the Pigeon Pose help release the posterior pull.

Abdominals: Use Cobra Stretches (lying face down, pushing up) to allow the spine to extension.

2. Strengthen (Underactive Muscles)

Hip Flexors: Perform Hanging Leg Raises or High Knees to encourage an anterior pelvic tilt.

Lower Back Extensors: Bird-Dogs or Supermans build the muscles that physically hold the arch.

Pelvic Tilts: Practice arching your back away from the floor while lying down to find the "neutral" curve.

Critical Notes

Avoid: Heavy squats or deadlifts if your form "winks" (rounds) at the bottom; this puts massive pressure on discs when the back is flat.

The "Why": If this was found on an MRI, it could be a protective muscle spasm. A physical therapist is necessary to distinguish between a structural bone issue and a simple muscle imbalance.

Are you experiencing any radiating pain down the legs, or is this mostly a postural correction?

>>77181531
OP here,
Thank you for the info!

No, I didn't have any radiating pain down the legs,
what I do have is "slicing" on the lower back on some movements

I've never had problems with back, but last year i did front squats and felt some sprain on the right side of the back where thoracic and lumbar spine connect
And i guess after that the "slicing" started

>>77181531
Thanks chatgpt

>>77181522
You need to do DL amd row

>>77181522
Haven't seen this pic in forever can't stop laughing

>>77181522
Kenny Smith at the analysis board