Execution of Distal Initiation (Slump-DI):
- Patient is in sitting position with an erect spine, legs hanging off the table and knees flexed to 90°
- First the examiner passively dorsiflexes the patient’s ankle to create distal pre-tension of the sciatic nerve tissue distal to the popliteal anchor point
- Then the patient tucks the chin in, forward flexes the neck and slumps the trunk, while the examiner gives overpressure on the head and neck, which creates maximal stretch on the dura
- At last, the examiner releases the dorsiflexion which will allow the dura to move back to the starting position
Execution of Proximal Initiation (SLump-PI):
- Patient is in sitting position with an erect spine, legs hanging off the table and knees flexed to 90°
- Then the patient’s head and neck are brought into flexion and the patient is asked to slump the trunk to create pre-tension of the sacral plexus in cranial direction
- Afterwards, the examiner passively dorsiflexes the patient’s ankle and extends the knee, which imposes maximal tension in the entire neural system from cranial to caudal
- At last, the patient is allowed to extend the head and neck which allows the dura to move distally to the starting position
Explanation:
The distal and proximal initiation of the Slump Test can be used to distinguish between fibrotic adhesions and primary-disc-related disorders like disc protrusions, prolapses or extrusions, which exert direct pressure on the nerve roots.
In case of a primary-disc-related disorder, the more the dura is tensioned, independent of the direction, the more pain will be provoked.
In case of late primary- or secondary-disc-related disorders, the Slump with distal initiation will be provocative in case of fibrotic adhesions, because the fibrotic adhesions impair dural sleeve mobility in distal direction.
In case of NRCS or INC (both secondary disc-related disorders), no pain will be produced during the different initiations of the Slump at all, because trunk flexion will increase the intervertebral space, which prevents compression of the nerve roots during any of the performed movements.
| Test | Primary disc-related disorders | Late primary /Secondary disc-related disorders | |
| Protrusion, Prolapse, Extrusion | Epidural adhesions | NRCS, INC | |
| Slump-DI | |||
| Ankle DF+Knee Ext. | Moderate pain provocation | Moderate pain provocation | No pain provocation |
| Neck and Trunk Fl. | Maximal pain | Less pain | No pain provocation |
| Ankle PF | Less pain | No pain provocation | No pain provocation |
| Slump-PI | |||
| Neck and Trunk Fl. | Mild pain provocation | No pain provocation | No pain provocation |
| Ankle DF and Knee Ext. | Maximal pain | No pain provocation | No pain provocation |
| Neck ext. + Head raise | Less pain | Moderate pain | No pain provocation |
| Study | Reliability | Sn | Sp | LR+ | LR- |
| Sizer et al. (2002) | NA | NA | NA | NA | NA |
| Comment: While these different build-ups of the Slump use sound structural clinical reasoning, no validity studies have confirmed or rejected this concept yet. | |||||
