Intrinsic Muscles of the Foot: A New Type of “CORE” Training for Runners and the Rest of Us

You would be hard-pressed to have a session with a physiotherapist, exercises specialist or personal trainer and not, at some point, have core strength or core stability come up.  Cue eye roll. The truth is it is widely shown to be extremely important in rehabilitation, athletic training and pretty much any activity of daily living Sulowska et al (2018). 

Stability of the core influences the mobility of distal body parts and the pattern of energy generation and transfer from proximal to distal segments.” (Read that again).

 

I was on an advanced lower limb physiotherapy course pre-COVID19 and the instructor referenced a school of thought (growing in its support by current research) that the intrinsic or small muscles of the arch of the foot are being called the core of the foot. Their job is to maintain the longitudinal medial arch of the foot much like the abdominal and spinal muscles maintain proper midline/spine mechanics. Sulowska et al (2018) reviewed literature which “indicates a relationship between the plantar short foot muscles and proximal segments with the functional of the body”. They further found support that the strength of these muscles is important for gait speed, step count and postural control. So, if you are going to pound the pavement by running, it could be argued that you would want your interface with you and the ground, your feet, to be firing at all cylinders properly. 

 

The authors of the article I reviewed basically identify the importance of good foot and lower leg strength as having an influence on the joints and muscles above. As a physiotherapist, I almost always give glute, hip, quad and hamstring strengthening to runners for self-care/performance enhancement and the muscles of the feet should be thought of as equally important. 

 

The aim of the Sulowska (2018) study was to “evaluate the influence of exercises of the plantar short foot muscles on the performance of lower extremities in long-distance runners”. They concluded that the inclusion of such types of exercise in the daily program for runners may improve energy transfer through body segments, increase the strength and values of generated power. The study has admitted limitations and looked at 47 runners aged 21-45 years who ran regularly for a range of 20-100 km per week.

Here is a break down of the exercises used performed for ~ 30 min a day for 6 weeks (for further details please see the cited reference below):

Vele’s Forward Lean (https://www.youtube.com/watch?v=blQxbxldZ14)

 

Reverse Tandem Gait (https://www.youtube.com/watch?v=blQxbxldZ14)

 

Short Foot Exercise (https://www.youtube.com/watch?v=9puHjMvnjdM)

 

  • Balance exercises on stability disc 2 and 1 leg stances.
  • Band resistance strengthening of ankle movements (plantar flexion, dorsiflexion, inversion, eversion)
  • Tennis ball rolling self-myofascial release prior to the above exercises. 

Work with your physiotherapist or running coach to determine ideal sets, reps, and duration for you and your training program. 

 

After the 6 week training period, the researchers observed increased 35 m sprint speeds, increased hamstring strength, improved overall foot posture and better functional movement screening test results.

 

The take-home message here is a simple and obvious one. If you run and or are on your feet and required to move at speed for any length of time, it may be very beneficial to make some or all of these exercises part of a regular training regime. I always say to patients that our bodies are like vehicles: the more mileage we put on them, the more regular and rigorous the maintenance routine must be to keep us on the road. Happy running and may all your cores remain stable!

 

References:

Sulowska I, Mika A, Olesky L and Stolarczyk A (2018). The influence of plantar short foot muscle exercises on the lower extremity muscle strength and power in proximal segments of the kinematic chain in long-distance runners. Hindawi BioMed Research International. Volume 2019, Article ID 6947273, 11 pages. http://doi.org/10.1155/2019/6947273