Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP)
A clinical measure of upper limb function in cervical spinal cord injury.
By Claire White
- Clinician-administered; about 45 minutes for the full assessment.
- Five subtests per hand: dorsal sensation, palmar sensation, strength, prehension ability, and prehension performance.
- Subtests are scored and reported separately. Their maxima add to 116 per hand.
- Designed specifically for tetraplegia, meaning cervical spinal cord injury.
Psychometrics
Reliability ranges across all five subtests, from Kalsi-Ryan and colleagues (2012), 72 neurologically stable participants assessed by two examiners over seven days. Higher is better.
What does the GRASSP measure?
The GRASSP assesses three domains of upper limb function in both hands. Sensibility is tested with monofilaments at three locations on the back of the hand and three on the palm. Strength grades ten muscles. Prehension is measured twice over, first as the ability to form three grasps, then as the performance of six grasps inside everyday tasks. That gives five scored subtests per hand, and a profile of hand function relevant to independence and to brain-computer interface research on grasping.
This page describes the structure of the assessment. The manual and the scoring criteria come with the GRASSP kit, which is published at grassptest.com.
What does a GRASSP result mean?
The five subtests are scored and reported separately, per hand. There is no composite total. The subtest maxima add to 116 per hand, but the assessment is read subtest by subtest, because that is where the clinical information sits.
| Subtest | What is scored | Range per hand |
|---|---|---|
| Dorsal sensation | 3 locations on the back of the hand, each 0 to 4 | 0 to 12 |
| Palmar sensation | 3 locations on the palm, each 0 to 4 | 0 to 12 |
| Strength | 10 muscles, each 0 to 5 | 0 to 50 |
| Prehension ability | 3 grasps, each 0 to 4 | 0 to 12 |
| Prehension performance | 6 grasps in functional tasks, each 0 to 5 | 0 to 30 |
Scores are tracked over time to show change in hand function. The smallest change that exceeds measurement error is about 5 points on strength, about 2 on prehension ability, and 5 to 7 on prehension performance. The result is reference information for the care team, not a diagnosis.
How the GRASSP is administered
- Administered by
- A clinician
- Time to administer
- About 45 minutes for the full assessment. A partial version is used early after injury.
- Equipment
- The GRASSP kit, with a Semmes-Weinstein monofilament minikit and standardised objects, plus manual muscle testing equipment
- Cost
- Free to take here.
- Published by
- grassptest.com
- Training required
- None formally. Reading the GRASSP manual is recommended.
- Available languages
- English
Which conditions is the GRASSP used for?
Related instruments
GRASSP questions, answered
How is the GRASSP scored?
Five subtests per hand, scored separately. Dorsal sensation and palmar sensation each test 3 locations from 0 to 4, so 0 to 12 each. Strength grades 10 muscles from 0 to 5, so 0 to 50. Prehension ability grades 3 grasps from 0 to 4, so 0 to 12. Prehension performance grades 6 grasps in functional tasks from 0 to 5, so 0 to 30. The subtests are read individually rather than summed into one number.
How long does the GRASSP take?
About 45 minutes for the full assessment on both hands. A partial version covering sensibility, strength, tone, and qualitative prehension is used in the early period after injury.
Who can administer the GRASSP?
A clinician. No formal certification is required, though the manual should be read first.
Is the GRASSP free?
Yes. It is free to take here. The GRASSP kit itself is published at grassptest.com, which is who to approach about administering it in your own practice.
How much change on the GRASSP is meaningful?
Above measurement error, about 5 points on strength, about 2 on prehension ability, and 5 to 7 on prehension performance. Over the first year after a cervical injury, strength changes most, with standardised response means of 0.79 to 1.48, then prehension at 0.50 to 1.03, then sensation at 0.14 to 0.64.
Why use the GRASSP instead of the ISNCSCI motor score?
Because the hand is where a cervical injury is felt, and the neurological exam does not look at it closely. The GRASSP is about 50 percent more sensitive to sensory and motor change in the upper limb, and it adds grasp, which the neurological exam does not test at all.
Evidence, psychometrics and provenance
Created by Sukhvinder Kalsi-Ryan and colleagues, with reliability and validity published in 2012. A second version, GV2, followed.
- Responsiveness, strength
- Standardised response mean 0.79 to 1.48 over the first year (Velstra, 2015)
- Responsiveness, prehension
- Standardised response mean 0.50 to 1.03 (Velstra, 2015)
- Responsiveness, sensation
- Standardised response mean 0.14 to 0.64 (Velstra, 2015)
- Sensitivity to change
- About 50 percent more sensitive to upper limb change than the standard injury classification
References
- 1.Kalsi-Ryan S, Beaton D, Curt A, et al. The Graded Redefined Assessment of Strength Sensibility and Prehension: reliability and validity. J Neurotrauma. 2012;29(5):905-914.
- 2.Kalsi-Ryan S, Curt A, Verrier MC, Fehlings MG. Development of the Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP): reviewing measurement specific to the upper limb in tetraplegia. J Neurosurg Spine. 2012;17(1 Suppl):65-76.
- 3.Velstra IM, Curt A, Frotzler A, et al. Changes in strength, sensation, and prehension in acute cervical spinal cord injury: European multicenter responsiveness study of the GRASSP. Neurorehabil Neural Repair. 2015;29(8):755-766.
- 4.Velstra IM, Fellinghauer C, Abel R, et al. Interval-level measurement properties of the GRASSP, a Rasch analysis. J Neurotrauma. 2018;35(6):854-863.
- 5.SCIRE Project. Graded Redefined Assessment of Strength, Sensibility and Prehension (GRASSP). Source for subtest ranges, administration time, equipment, kit cost, training, and languages.
This assessment uses a validated instrument and is reference information, not a diagnosis.