Machine back extension vs Machine Reverse Hyperextension
Swapping Machine back extension (Machine) for Machine Reverse Hyperextension (Machine) retains 100% overlap; expect externally braced cam track. Compare exact 17-muscle fractional recruitment before swapping equipment mid-session.
Side-by-Side 17-Muscle Recruitment Delta
How primary mover (1.0× set) and synergist (0.5× set) allocation changes when swapping Machine back extension for Machine Reverse Hyperextension.
| Muscle Group | Machine back extension | Machine Reverse Hyperextension | Leverage Shift |
|---|---|---|---|
| Hamstrings | Primary (45%) | Primary (45%) | Matched |
| Glutes (Gluteus Maximus / Medius) | Primary (35%) | Primary (35%) | Matched |
| Lower Back (Spinal Erectors) | Secondary (20%) | Secondary (20%) | Matched |
Load & Volume Conversion: Machine back extension → Machine Reverse Hyperextension
Worked weight heuristic: a 115 kg set on Machine back extension (Machine) maps roughly to 115 kg on Machine Reverse Hyperextension (Machine; 5 kg jumps, curve: cam-matched resistance across sticking points). Calibrate set 1 at RPE 8 so e1RM history for Machine back extension remains unskewed. Zero anatomical muscles are dropped between Machine back extension and Machine Reverse Hyperextension; 1:1 weekly set volume carries straight across.
Supporting Sports-Science Literature
| Study Title | Lead Author & Year | Verified Link |
|---|---|---|
| Influence of joint position on electromyographic and torque generation during maximal voluntary isometric contractions of the hamstrings and gluteus maximus muscles. | Worrell (2001) | PubMed 11767248 ↗ |
| Progressive overload without progressing load? The effects of load or repetition progression on muscular adaptations. | Plotkin (2022) | PubMed 36199287 ↗ |
| Effect of hand position on EMG activity of the posterior shoulder musculature during a horizontal abduction exercise. | Schoenfeld (2013) | PubMed 23302754 ↗ |
| Changes in rectus femoris architecture induced by the reverse nordic hamstring exercises. | Alonso-Fernandez (2019) | PubMed 30293403 ↗ |