The Efficacy of Ischemic Preconditioning on Handgrip Strength and Strength Endurance in Para-Athletes With Spinal-Cord Injury: A Pilot Study

Abstract

Purpose: This pilot study investigated the functional outcomes after ischemic preconditioning (IPC) in high-level para-athletes with spinal-cord injury. Methods: Nine athletes completed 2 handgrip exercise trials (an isometric hold to failure at 60% maximal voluntary contraction [ISO] and a progressive, intermittent handgrip to failure [INT]), preceded by either IPC (220 mm Hg) or sham (20 mm Hg) for six 5-minute periods, in a repeated-measures, crossover design. Results: Although small performance improvements in time to task failure were observed in the ISO (∼5%) and INT (∼8%) IPC conditions, which are similar to those reported elsewhere, no statistical influence was observed (ISO–IPC, 74.2 [32.6] s; SHAM, 70.7 [27.2] s; P = .73; INT–IPC, 426.0 [80.1] s; SHAM, 392.2 [42.5] s; P = .35). Fatigue was evident in the forearm muscle force (maximal voluntary contraction) ISO (mean decline of 178.1 [76.0] N [95% CI, −10.4 to 366.7 N]; P < .05) and INT (mean decline of 182.2 [72.5] N [95% CI, 34.5–329.8 N]; P < .05) trials but not different between treatments (P > .95). Conclusions: Although small performance improvements in time to task failure were observed, the findings of the present data set suggest that acute bouts of IPC do not meaningfully influence fatigue during handgrip exercise in para-athletes with spinal-cord injury.