Biomechanics experts gathering at Calgary International Society of Biomechanics Conference (Part 1/2)
I recently attended the International Society of Biomechanics Conference in Calgary. This conference gathers biomechanical scientific experts across a range of areas. I attended most of the running sessions. Here are interesting citations and key results from the speakers. Note that The Running Clinic and myself do not necessarily agree with all of these!
1. Paquette MR – Are we moving forward in research on risk factors for running-related injuries?
The association between biomechanical variables and prospectively injured runners is inconsistent. The problem with the current research is the use of a single biomechanical testing session that does not consider day-to-day variability in running training.
2. Jungmalm J – Development of overuse injuries in running - A multidisciplinary approach
In a prospective cohort study, 224 half marathon recreational runners were monitored for 1 year after baseline testing that included a range of anthropometrical, clinical, and biomechanical measures (age, sex, body mass index, range of motion, strength, flexibility, trigger points, 3D kinematics, etc.). Runners with weaker hip abductors in relation to adductors and late rearfoot peak eversion (a component of pronation) sustained more injuries.
3. Sørensen H – Combining biomechanics and epidemiology in running injury research
We need to combine biomechanical AND epidemiological data to understand running-related injuries. We need to confirm the extent to which we can estimate biomechanical data from GPS watches for monitoring runners and running-related injuries.
4. Napier C – Beyond “How hard did it feel?” What can we gain from the use of wearable sensors to monitor training loads in running?
Research on running-related injuries indicate that biomechanics do matter, but research on anatomy is conflicting. Replacing the word “anatomy” with “genetics” is probably more appropriate.
Preliminary data from a 26-week prospective study on 104 runners with 32 running-related injuries indicate that use of internal training load monitoring (Time x rating of perceived exertion) is sufficient for running-related injuries. Data do not support use of wearable sensors for this purpose.
RUNNING INJURIES – TIBIAL STRESS FRACTURES
5. Esposito M – Effects of load carriage on biomechanical variables associated with tibial stress fractures in running
In soldiers, tibial stress fractures are common as load carriage over 25 lbs increases tibial stress. Biomechanical variables (instantaneous loading rates) associated with tibial stress fractures are no different between 0, 10, and 25 lbs, but higher at 50 lbs. Peak rearfoot eversion was greater at 25 and 50 lbs than 0 and 10 lbs. Previous experience and location of load carriage influence biomechanical adaptation to load carriage.
6. Mattock J – Does calf muscle morphology and function differ between mtss symptomatic and asymptomatic long-distance runners?
Runners with medial tibial stress syndrome (n = 8) had similar calf muscle girth than non-injured runners (n = 8), but thicker gastrocnemius medialis and lateralis muscles on ultrasound assessment and reduced functional capacity on calf muscle endurance testing (35 vs 113 single-leg calf raises).
7. Van Den Berghe P – Multi-directional peak tibial accelerations in over-ground, level, running: a multicenter study
The resultant peak acceleration is higher and the axial peak acceleration is lower in non-rearfoot strikers compared to rearfoot strikers when accelerometers are placed on the lower leg. Axial peak and resultant peak accelerations are not the same – resultant is more reliable.
8. Matijevich E – Wearables and injury prevention: the pitfalls and opportunities for monitoring musculoskeletal loading
Ground reaction force is a weak predictor of internal tibial loading (r = 0.20). Active peak ground reaction force is a better predictor (r = 0.72), but is still limited. The association between lab-based running accelerometer metrics and field-based running accelerometer metrics were the highest (r > 0.80). The hardware exists…the solution might lie in the appropriate algorithm!
9. Meardon S – Estimating bone stress at the distal tibia during running using external transducers
Ground reaction force variables show no significant relation to bone stress when taken alone. Tibial acceleration is more strongly related to bone stress, and including bone geometry improves this association.
RUNNING INJURIES - PATELLOFEMORAL PAIN
10. Baggaley M – Maximizing caloric expenditure and minimizing patellofemoral joint loading during running
Steep uphill running reduces the time needed to burn 500 kcal by 10 minutes without increasing cumulative loads. Moderate grade running (±5°) increases caloric expenditure without increasing patellofemoral joint loading.
11. Wang B – Effects of a 12-week gait retraining intervention on knee loadings in runners
Nine recreational rearfoot runners ran for 3 gait retraining sessions per week using minimalist shoes, 5 to 48 minutes per session, increasing across 12 weeks. Seven runners converted to a forefoot strike pattern. These runners had 15% lower knee extensor moments and 14% lower patellofemoral joint stress when running in minimal shoes at the end of training, but not in cushioned shoes.
12. Kernozek T – Effects of added load on patellofemoral joint stress in running
Adding a 9 kg weighted-vest load increases patellofemoral joint loads (peak stress, peak reaction force, and peak quadriceps force) in females with no changes in temporal-spatial variables (e.g. cadence) or knee range of motion.
13. Wu T – The effect of different and modified foot progression angle on patellofemoral pain related factors
Increasing foot progression angles 15° (toe out) in running decreased knee abduction and hip adduction angles, but did not change joint moments and kinetics (forces). Interventions used to decrease knee loading during walking are not appropriate for running gait.
14. Gheidi N – Effect of running velocity on patellofemoral joint stress
Increasing running velocity from 2.8 to 3.8 m/s increased patellofemoral joint stress in 29 female rearfoot strikers. Increases in stride length and quadriceps force are the primary factors linked to the increased patellofemoral joint stress.
RUNNING FOOTWEAR: BIOMECHANICS AND PERFORMANCE
15. Hoogkamer W – Footwear compliance: implications for running economy and distance running performance
Energy return is an important concept in running footwear compliance. Both softness and resilience are needed in cushioned shoes for performance. The Nike Vaporfly energy return is 87%, Adidas Boost is 76%, and Nike Zoom is 66%. The Nike Vaporfly resulted in the lowest energy cost.
16. Farina EM – Footwear creation process for improving the performance of marathon running
The effect of plate geometry on energy lost during running was examined in four Nike prototype shoes: no plate, flat curve plate, moderate curve plate, and an extreme curve plate (Nike Vaporfly). The extreme curve plate reduced the net energy lost at the big toe (metatarsophalangeal joint) without increasing ankle demands.
17. Giandolini M – Midsole material properties affect the amplitude but not the frequency of soft-tissue vibrations in heel-toe runners
Tissue vibration can lead to discomfort in runners. The amplitude of soft tissue vibration and muscle activity is lower in shoes with a viscous midsole in heel strikers (muscle tuning), but frequency of vibration is the same. The comfort perception of runners was not reliable (same shoes tested twice provided different comfort levels).
18. Davis I – Why movement matters
Movement is critical for healthy brains. Our environment is changing faster than our bodies can adapt. We are not living the lives or running the way our bodies were designed for.
Globally, there appears to be an association between hip adduction and high impact loading that lead to running-related injuries. Reducing these mechanics should reduce the risk of running-related injuries.
We need to acquire and transfer to internalise a motor skill. Faded feedback is efficient in gait rehabilitation. Feedback is powerful.
Does footwear matter? Yes, there are interactions between footwear and the foot strike pattern. The cross-sectional area of the foot reduces 10 – 17% after wearing orthotics for 12 weeks. Forefoot striking and minimal shoes increase cross-sectional area and stiffness of the Achilles tendon. Develop foot abs of steel (foot intrinsic muscles)! Running research is now going “in the wild” using wearable technology.
19. Paquette M – Acute footwear effects on ankle and knee kinetics in inexperienced and experienced runners
Experience matters for running kinematics and kinetics, particularly at the knee. Running experience did not influence the observed footwear effects.
20. Moore I – Footwear effects on running economy and stride characteristics in experienced runners
At a group level, there is not much change in metabolic cost with footwear in experienced runners. Inexperienced runners showed better running economy in minimalist shoes. Individual variations in response to footwear changes were noted.
21. Zhang X – Mechanical adaptation of Achilles tendon after a 12-week minimalist running transition program
Achilles tendon force and mechanical properties of runners increased across 12 weeks when given minimalist shoes (INOV-8 BARE-XF 210 v2). Achilles tendon force increased more in runners that were also retraining to transition to forefoot running.
22. Arndt T – The effects of running in minimalistic shoes on non-uniform displacement in the Achilles tendon
A study involving three foot strike patterns (forefoot, midfoot, rearfoot), three footwear conditions (barefoot, minimalist, traditional), and speckle tracking ultrasound of the Achilles tendon in runners showed increased displacement of the deep Achilles tendon, lower displacement of the superficial Achilles tendon, and more displacement non-uniformity of the Achilles tendon from barefoot to traditional shoes.