###### Abstract  
Rigid leukocyte applied to the skin of the trunk dorsum, superficial to the lumbar paraspinals, has been shown to reduce lumbar flexion in repetitive lifting, with the potential to reduce the risk of injury in jobs requiring the handling of material. It is unclear which mechanism underpins this reduction, and whether a tape with more elastic properties (i.e., kinesio tape) can yield similar results. In this study, twelve participants were randomly allocated into two groups, and practiced a repetitive lifting task with either leukotape or kinesio tape applied to the skin of their trunk dorsum. The participants also performed a sagittal plane repositioning task to assess changes in lumbar proprioception. The results showed a small reduction in lumbar flexion in the kinesio tape group and a moderate reduction in the leukocyte group, and suggested a reduction in repositioning errors in the kinesio tape group only. We suggest that leukocyte may correct the movement and improve performance during a flexion-based task, while kinesio tape may improve lumbar proprioception and promote learning. These results have implications for the choice and use of wearable textiles aiming to reduce injury risks in the manual handling industry. augmented feedback; tactile feedback; practice design; low back; spine +
Footnote †: journal: Medical  
specialized mechanoreceptors (slowly adapting type 2, Ruffini corpuscle) sensitive to tensile strain, which have been postulated to play a critical role in proprioception [8]. Further, in flexed spine postures, skin stretch sensitivity thresholds decrease in the longitudinal direction [9]. This suggests that a flexed posture can cause the skin to \"pre-stretch\", lowering the threshold of mechanically sensitive afferents to sense an additional stretch [10]. The improvement of stretch sensitivity can be used for the design of a tactile feedback strategy. Specifically, a tape can be applied to the skin parallel to the spine to augment skin stretching, providing supplemental sensory information about spine flexion, particularly in high-flexion postures. Based on this, two studies have recently shown that a rigid sport leukocyte applied to the lumbar extensor muscles reduced lumbar flexion during lifting [7; 11]. Yet, it remains unclear which mechanism underpinned this reduction, and if tape with differing elastic properties may modulate this effect. Examining the mechanism that underlies a feedback effect is not a trivial issue in motor learning [12]. Feedback can promote a short-term improvement in performance by guiding movement, or promote a lasting learning effect by directing a learner's attention to critical goal-related sensory information. In the former, the effect reduces when the feedback is removed (i.e., feedback dependency), while it persists in the latter [13]. Knowing which mechanism a feedback strategy promotes is critical for the design of a training or re-training intervention. Previous research suggested two potential mechanisms for the effect of leukocyte on reducing lumbar spine flexion. [PERSON] et al. [7] showed that participants retained reduced lumbar flexion when the tape was removed, suggesting that leukocyte could improve body awareness (i.e., lumbar proprioception) by making sensory information more accessible. Supporting this explanation, [PERSON] and [PERSON] [14] revealed small improvements in proprioception in a trunk repositioning task when participants wore a lumbar brace. However, [PERSON] et al. [7] also stated that the leukocyte may have acted as a mechanical barrier (some participants reported this). In fact, the second explanation for a reduced lumbar angle is that leukocyte could act as position control, limiting participants' movement and preventing them from flexing their spine. [PERSON] et al. [11] found some indication that participants became dependent on the feedback provided. These authors argued that the tape initially restricted participants in flexing their spine, and this effect decreased once the tape was removed.