Effect of work boot shaft stiffness and sole flexibility on boot clearance and shank muscle activity when walking on simulated coal mining surfaces: implications for reducing trip risk

Abstract

Mining work boot shaft stiffness and sole flexibility variations are likely to affect how a miner moves their foot to clear the ground thus influencing their risk of tripping. Despite the potential negative consequences associated with tripping, limited research has investigated how these boot design features might contribute to a miner’s trip risk. Therefore, this study aimed to investigate the effects of systematic variations to boot shaft stiffness and sole flexibility on lower limb alignment and shank muscle activity at toe off and boot clearance during initial swing when 20 males walked across two simulated coal mining surfaces. Although knee and hip alignment remained constant, changes to boot shaft stiffness and sole flexibility significantly interacted to influence the shank muscle activity and ankle alignment displayed at toe off. To reduce the risk of tripping, underground coal miners should avoid a boot with a stiff shaft, regardless of the sole flexibility.

PRACTITIONER SUMMARY

Underground coal miners experience a high incidence of work-related lower limb injuries, with tripping a main cause. This study systematically investigated two boot design features that are likely to influence a miner’s risk of tripping. To reduce trip risk, coal miners should avoid a boot with a stiff shaft.

Keywords:

• Boot design
• mining
• uneven terrain
• electromyography
• kinematics
• lower limb injuries

Acknowledgement

The authors wish to acknowledge the contribution of our industry partner, South32, for their gracious assistance with resources and participant recruitment, to Mack Boots for providing the prototype test boots, and Jessica Laing (www.seeillustrationsfordetails.com.au) for assistance with the illustrations. This research has been conducted with the support of an Australian Government Research Training Program Scholarship.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by the Coal Services Health and Safety Trust [HST Project No. 20620].