Acute effects of an isometric neck warm-up programme on neck performance characteristics and ultrasound-based morphology

Abstract

Objective

Athletic performance can be enhanced immediately after an isometric warm-up, a phenomenon termed post-activation performance enhancement (PAPE). While isometric warm-ups can improve lower extremity sprint and jump performance, neck-specific isometric warm-ups need development and validation for mild traumatic brain disorders and neck pain. This study examined acute effects of isometric warm-ups on neck performance and morphology.

Methods

Arm 1: Twenty-six adults (13 M:13F) completed neck performance testing before and after a 10-minute neck isometric warm-up or stationary bike (sham) between two visits. Testing included visual-motor reaction time, peak force, rate of force development, force steadiness, and force replication/proprioception measured by a 6-axis load cell. An inclinometer assessed range-of-motion. Paired t-tests and two-way ANOVA examined effects of neck/bike warm-up and interaction effects, respectively. Arm 2: 24 adults (11 M:13F) completed ultrasound scans of cervical muscles: before 20-minute rest (sham), and before/after a 5-min neck isometric warm-up. Longus colli cross-sectional area and sternocleidomastoid/upper trapezius thickness and stiffness, and cervical extensors thickness was assessed. One-way ANOVA compared morphological values at sham, before, and after warm-up. Significance was set at p < 0.05.

Results

Isometric neck warm-up increased rate of force development in flexion (p = 0.022), extension (p = 0.001–0.003), right lateral flexion (p = 0.004–0.032), left lateral flexion (p = 0.005–0.014), while peak force improved only in left lateral flexion (p = 0.032). Lateral flexion range-of-motion increased after neck warm-up (p = 0.003-0.026). Similarly, longus colli cross-sectional area (p = 0.016) and sternocleidomastoid thickness (p = 0.004) increased.

Conclusions

Increased neck performance characteristics and morphology are likely due to PAPE effects of isometric neck warm-up. For coaches and athletes, simple isometric contractions could be added to existing warm-ups to reduce prevalence, incidence, and severity of mild traumatic brain injuries and neck pain.

Keywords:

• Isometric
• warm-up
• cervical
• neck
• force development
• proprioception
• sensorimotor
• performance enhancement

Disclosure statement

There are no conflicts of interest for all authors. The views expressed in this manuscript are those of the authors and do not reflect the official policy of the Department of Army, Department of Defense, or the U.S. Government.

Funding information

Funding was provided by the Mayo Clinic Ice Hockey Research Group, NIH awards L30AR070273 (NDS) and K12HD065987 (NDS), and the Florida Department of State Center for Neuromusculoskeletal Research.

Data availability statement

Data are available upon reasonable request.