Runner with Recurrent Hamstring Strain and Poor Lumbo-Pelvic Control
Dev is a 26-year-old sprinter with two right biceps femoris strains in the past 12 months, both during acceleration out of blocks. He has completed return-to-run and is now pain-free, but his single-leg bridge shows right hip drop and lumbar extension at the top, his prone plank is 45 seconds with breath holding, and he cannot keep a neutral spine during a dead bug when the opposite leg extends. His coach has prescribed daily planks, side planks, and back extensions. Dev believes his core is weak and wants to add more holding exercises. He trains six days per week and has 15 minutes for core work on sprint days. He has a history of low back tightness but no current pain.
1. Prioritize the motor-control problem. Which system or strategy is failing, and why are planks and back extensions poor first choices for this athlete?
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Priority: lumbo-pelvic control under distal load, not more plank time. His single-leg bridge shows hip drop and lumbar extension, which means he is using lumbar extension and global extensor dominance to substitute for hip extension and trunk stiffness. The dead-bug failure confirms he cannot dissociate leg movement from lumbar position.
Why planks and back extensions are poor first choices:
- A 45-second prone plank with breath holding trains endurance in a held position, but it does not train the timing of deep trunk and hip muscles during acceleration. He can already hold it; more holding does not transfer to sprinting.
- Back extensions reinforce lumbar extension, which is his compensation. They may increase extensor capacity but not the control he lacks.
- Side planks are useful for lateral trunk endurance but do not address the hip-drop and extension strategy seen in single-leg loading.
Motor-control target: train anti-extension and anti-rotation with breathing, then single-leg hip extension with a stable pelvis. The goal is to make the correct strategy automatic under increasing speed and load.
2. Design a 3-step progression for the dead bug and single-leg bridge, including dosage, cue, and progression criterion. Explain how each step targets the identified deficit.
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Progression:
- Dead bug with exhale, one leg only. 2 x 6 per side, 3-second reach, exhale on reach. Cue: keep the low back heavy on the floor; reach the heel, not the ribcage. Progress when he can keep the rib-pelvis relationship for 8 clean reps with a 5-second hold.
- Dead bug with opposite arm and leg, then band-resisted. Add a light band around the feet or a pull-down. 2 x 5 per side. Purpose: add distal load while maintaining trunk position.
- Single-leg bridge with a 5-second hold and marching. 2 x 6 per side, hold at the top and lift the opposite knee 2 cm. Cue: keep the belt line level; push the ground away. Progress to single-leg bridge from a bench with the same criterion.
Dosage: 2-3 times per week on sprint days, 10-15 minutes, leaving 2 reps in reserve. Progression criterion: no lumbar extension, no hip drop, and no breath holding for two sessions. Then add speed or a small load, not more volume. Why: each step increases distal demand while keeping the pelvis accountable, which is the specific deficit.