Skin temperature and muscle blood volume changes in the hand after typing

Several studies have measured altered hand skin temperature in response to typing. It is unknown whether this measure is indicative of an underlying change in muscle perfusion or merely reflective of skin capillary shunting. The objective of this pilot study was to examine the correlation between mean skin temperature (THand), and relative blood volume (RBV) in the first dorsal interosseous muscle as measured through near infrared spectroscopy in the hand after a 9-min typing task in (n = 10) healthy subjects. Additionally, the effect of typing speed on the physiological measures was determined. THand relative to baseline and RBV were moderately correlated during 10 min post-typing (Pearson correlation coefficient [PCC] = 0.75, p = 0.01 at 0–2 min after typing; PCC = 0.52, p = 0.12 at 3–5 min after typing; PCC = 0.77, p = 0.01 at 8–10 min after typing). A typing speed of greater than 50 words per minute affected both RBV and THand, with both measures normalizing more quickly among faster typists, indicating a possible metabolic influence on both measures. Skin temperature after typing does appear to reflect underlying muscle perfusion in the hand.Relevance to industryReduced blood flow has been implicated in musculoskeletal disorder (MSD) pathophysiology. The current study examined two objective non-invasive measures after a low-intensity task in healthy subjects. Further studies should examine the post-task pattern in symptomatic individuals to determine the suitability of using these physiologic measures to indicate the presence of MSDs.