FOOT FUNCTION AND JOGGING
‘Jogging’ has been defined as ‘sub-maximal’ running, typically at speeds between 6-10mph (10-16km/h). Biomechanically, jogging is a ‘hybrid’ gait with characteristics of walking and running. Using one or both of these definitions of jogging means 80-95% of recreational ‘runners’ are actually ‘Joggers’. When jogging, the knee and hip act like ‘springs’ as in running, but the foot and ankle act as ‘rockers’ with the same heel-toe pattern as walking. Jogging places the ankle and foot rockers under considerable load compared to walking. The forces acting on the leg during the support phase double from 120% bodyweight when walking to over 250% bodyweight when jogging. The range of movement required at the ankle also increases from a minimum of 10 degrees dorsiflexion when walking to a minimum 20 degrees dorsiflexion when jogging. Both of these facts play a role in the high injury rates experienced by joggers. Any injuries or pains associated with the biomechanical compensations used during walking (e.g. toeing out, over pronation, heel pain etc.) will be exaggerated and aggravated when jogging.
The knee joint is particularly vulnerable to overloading and injury during jogging when toe structure and function is compromised and jogging technique is poor. Toe function is essential for injury-free jogging as they ‘anchor’ the foot and determine the trajectory of the knee joint over the foot during the support phase. The action of the toe flexors and extensors also play an important role in assisting the shin muscles in decelerating the foot and tibia during the entire ground contact phase. Weakness in the toe muscles is associated with anterior and posterior ‘shin splints’.
The key features required in a ‘jogging shoe’ are:
- An anatomical toe box (wide, flat and foot-shaped) is essential to allow the toes to provide maximum stability and leverage and allow the toe flexors and extensors to assist the anterior and posterior shin muscles.
- Appropriate cushioning. Due to the high impact forces associated with jogging a ‘jogging shoe’ should provide an appropriate amount of cushioning to protect the heel and metatarsal bones. The human foot has evolved fat pads to protect these areas of the foot, but these pads can literally wear out from excessive loading, particularly if the jogger has a rigid shoe-shaped foot and is over 40 years old.
The biomechanics of human locomotion can be explained by the physics of pendulums and springs. Humans have essentially four locomotive strategies available: walking, jogging, running, sprinting.
- These locomotive strategies become progressively less pendulum like and more spring like as speed and gravitational loading increase and contact time decreases (see diagram).
- Each locomotive strategy has energetic and biomechanical consequences i.e. metabolic cost and risk of injury.
- Skillful human movement is characterised by adopting the locomotive strategy for a given speed and terrain that maximises economy while minimising injury risk.
- Movement strategy selection is influenced by several factors including habit, conditioning and accurate sensory feedback about the external environment.
Perry J. Gait Analysis: Normal and Pathological Function. SLACK inc (1992)
Kuo AD et al. Energetic consequences of walking like an Inverted pendulum: step-to-step transitions. Exercise and Sport Sciences Reviews (2005)
Doke J et al. Mechanics and energetics of swinging the human leg. The Journal of Experimental Biology (2005)
Hughes J et al. The Importance of the toes in walking. The Journal of Bone and Joint Surgery (1990)
Lambrinudi C. Use and abuse of toes. Post Graduate Medical Journal (1932)
Bowerman WJ. Jogging. Corgi (1967)
Cavanagh PR . Ed. The Biomechanics of Distance Running. Human Kinetics (1990)
Bosch F, Klomp R. Running: Biomechanics and Exercise Physiology Applied in Practice. Elsevier (2005)
De Almeida MO et al. Is the rearfoot pattern the most frequent foot strike pattern among recreational shod distance runners? Physical Therapy in Sport (2015)
Pink M et al. Lower extremity range of motion in the recreational sport runner. The American Journal of Sports Medicine (1994)
Mei Q et al. Investigating biomechanical function of toes through external manipulation integrating analysis. Acta of Bioengineering and Biomechanics (2015)
Cavanagh PR et al. Pressure Distribution under symptom-free feet during barefoot standing. Foot & Ankle (1987)
Drewes LK et al. Dorsiflexion deficit during jogging with chronic ankle instability. Journal of Science and Medicine in Sport (2008)
Jahss MH et al. Investigations into the Fat Pads of the Sole of the Foot: Anatomy and Histology. Foot & Ankle (1992)
Jahss MH et al. Investigations into the Fat Pads of the Sole of the Foot: Heel Pressure Studies. Foot & Ankle (1992)
Ozdemir H et al. Effects of changes in heel fat pad thickness and elasticity on heel pain. Journal of the American Podiatric Medical Association (2004)
Mann RA, Hagy JL. Biomechanics of walking, running and sprinting. The American Journal of Sports Medicine (1980)
Mann RA, Hagy JL. The Function of the toes in walking, jogging and running. Clinical Orthopaedics and Related Research (1979)
Novachek TF. The biomechanics of running. Gait and Posture (1998)
Kyrolainen H et al. Changes in muscle activity with increasing running speed. Journal of Sports Sciences (2005)
Nummela AT, Keranen T. Factors Related to top running speed and economy. International Journal of Sports Medicine (2007)
Dorn TW et al. Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance. The Journal of Experimental Biology (2012)
Bushnell T, Hunter I. Differences in technique between sprinters and distance runners at equal and maximal speeds. Sports Biomechanics (2007)
Korhonen MT et al. Age-related differences in 100m sprint performance in male and female mas- ter runners. Medicine and Science in Sports and Exercise (2003)
Wilkinson et al Feet and footwear: applying biological design and mismatch theory to running injuries. International Journal of Sports and Exercise Medicine (2018)