• Siddall, Andrew
• Stevenson, Rich
• Stokes, Keith
• Turner, Philip
• Bilzon, James

Abstract

Firefighters require a certain degree of muscular strength to safely and effectively perform essential operational tasks. However, insufficient evidence exists to inform on the occupational strength requirements of firefighters. This study aimed to determine optimum strength standards for operational duty by examining the relationship between criterion tasks and surrogate gym-based exercises. Generic firefighting tasks that required the largest applications of physical strength and minimum acceptable performance of these tasks were identified and endorsed by a technical panel comprising operationally experienced experts. Fifty one (26 male, 25 female) civilian (non-firefighter) volunteers (mean (±SD): age 24 (±6) y, mass 74 (±15) kg, height 1.72 (±0.1) m, BMI 25 (±4) kg.m-2, estimated body fat 21 (±8)%) completed a series of tasks in a randomised order. Discrete performance (pass/fail) was assessed on three criterion tasks; a ladder lift, a ladder “extend-to-lower” and a ladder extension. Maximum performance was also measured on surrogate representative gym-based tasks; 1 repetition maximum (1RM) seated barbell overhead press, 1RM rope pull-down and a repeated 28 kg rope pull-down (repetitions to failure). Receiver-operator characteristic (ROC) curves were plotted to determine optimum performance standards that were mathematically closest to maximising sensitivity (true positive rate) and specificity (false positive rate). Mean (±SD, range) shoulder press 1RM of those who passed (n=31) and failed (n=20) the ladder lift test were 53 (±13, 35-75) kg and 25 (±5, 20-32.5) kg, respectively. Mean (±SD, range) single rope pull-down 1RM of those who passed (n=39) and failed (n=12) the ladder extend-to-lower test were 76 (±19, 46-109) kg and 48 (±9, 30-60) kg, respectively. Mean (±SD, range) repetitions to failure of 28 kg rope pull-down of those who passed (n=36) and failed (n=15) the ladder extension test were 37 (±16, 10-68) and 13 (±9, 1-34), respectively. Optimal performance standards were calculated as 35 kg for shoulder press (sens/spec: 1.00/1.00), 60 kg for single rope pull-down (sens/spec: 0.76/0.92) and 23 repetitions for the 28 kg repeated pull-down (sens/spec: 0.81/0.93). Surrogate gym-based strength tests were investigated as predictors of performance on strength and muscular endurance tasks critical to firefighting, resulting in obtainment of suitable performance measures. These findings facilitate the use of normal gym-based practices for testing optimal strength for operational duty as a firefighter. Since the physical demands of firefighting roles are multi-faceted, combining these findings with cardiorespiratory demands could aid firefighting populations in the maintenance of appropriate fitness for work.

Topics

• strength
• positron annihilation lifetime spectroscopy
• Photoacoustic spectroscopy