Secondary Voice Outcomes of a Randomized Clinical Trial Comparing Two Head/Neck Strengthening Exercises in Healthy Older Adults: A Preliminary Report

Purpose: The aim of this study was to investigate secondary voice outcomes and detraining effects of 2 head and neck strengthening exercises, which have been used in swallowing rehabilitation, that is, the head-lift exercise (HLE) and the recline exercise (RE), in healthy older adults. Method: Twenty-seven healthy older adults (between 60 and 85 years of age) were randomized to perform either the RE or the HLE for a 6-week period. Isometric and isokinetic portions of the exercise were performed 3 times daily. Patients were evaluated at baseline, postexercise, and following a 6-week detraining period. Acoustic outcome measures included the highest and lowest frequencies of vocal range on pitch glides (measured in hertz) and cepstral peak prominence on sustained vowels and connected speech. Self-perceptual measures included perceived phonatory effort. Results: Twenty-two individuals completed their assigned exercise regimen. No significant differences between exercise groups were observed at baseline for age, body mass index, or body fat percentage. A significant postexercise increase was seen in the highest frequency of vocal range on pitch glide, t(2, 56.79) = -10.28, p = .0001, for both groups. This increase was not fully maintained following the 6-week detraining period; however, data remained significantly above baseline at this time point, t(2, 57.01) = -4.70, p = .0001. Seventeen of the individuals who made postexercise gains were followed postdetraining. On average, these 17 individuals maintained 51% of their postexercise gains in the highest frequency of vocal range. No differences were observed between exercise groups. In addition, no significant changes in the lowest frequency of vocal range, cepstral peak prominence on sustained vowels or connected speech, or perceived phonatory effort were observed following the exercise regimens. Conclusions: Both the HLE and the RE produced gains in the highest frequency of vocal range in healthy older adults. This finding is promising; however, further research is required to understand how suprahyoid muscle strengthening influences upper pitch range and whether this relationship has potential clinical implications for patients with dysphonia.