Kendall et al. 2005
USA
PEDro=9
RCT
Initial N=9; Final N=8

Population: SCI: Level of injury: C5/C6; Severity of injury: AIS: A-C; Time since injury = 16.5yrs.
Treatment: Subjects were randomized into one of two groups.  They either received creatine or placebo, then following a wash out period they received the other medication.
Outcome Measures: Hand function was assessed by using the Grasp & Release Test (GRT). Subjects completed the Functional Independence Measure.  Looked at eating, grooming, dressing and transferring.

No significant findings were noted between:

• Placebo and supplementation conditions;
• Endurance times between the two treatments;
• The mean summed GRT scores for creatine and placebo.

Jacobs et al. 2002
USA
PEDro=8
RCT (cross-over design)
N=16

Population: Mean age=35.3 yrs; Gender: males = 16; Level of injury: tetraplegia; Weight = 71.4 kg.
Treatment: 2 phases: 1 week each, with a 3 week washout period in between. Trial A had 20 g of creatine monohydrate 4x/day mixed with 8 ounces of water. Trial B substituted placebo maltodextrin powder for creatine.  Peak arm ergometry test was completed on Day 1 & 7 for each trial.
Outcome Measures: Peak power output; Time to fatigue; Heart rate (HR); Metabolic measurements – Oxygen uptake (VO2), Minute ventilation, Minute ventilation (VE), Ventilatory frequency (VF), Respiratory exchange ratio (RER), Tidal volume (VT).

• No adverse effects found.
• HR, RER & VE: no change. VO2, VCO2, VF & VT: significant differences between trials (p<0.001).
• VO2 ↑ 18.6% with creatine vs. placebo.
• After creatine consumption:
• VO2, VCO2 & VT reached highest peak 
• ↑ peak power output (p≤0.05).
• ↓ peak VF (p<0.001).