Differences in Foot Biomechanics and the Effect of Foot Core Exercises or Foot Orthotics in Symptomatic Flexible Flatfoot
Overview
- Phase
- N/A
- Intervention
- Not specified
- Conditions
- Flatfoot, Flexible
- Sponsor
- KU Leuven
- Enrollment
- 48
- Locations
- 1
- Primary Endpoint
- Change in lower limb joint angular velocities (degrees/second)
- Status
- Completed
- Last Updated
- last year
Overview
Brief Summary
The overall goal of this study is to evaluate the effect of a foot strengthening program (focused on the intrinsic foot muscles) on ankle and foot joint kinematics and kinetics (rearfoot, midfoot, and forefoot) in patients with symptomatic flexible flat feet. The investigators will also evaluate the effect on intrinsic muscle morphology, foot strength, pain and other symptoms. The investigators will compare to the standard conservative therapy, which is foot orthotic therapy.
Detailed Description
A common condition is "symptomatic flexible flat foot". This clinical entity affects 1 in 5 adults and is characterized by misalignment of the foot joints, resulting in a flat medial longitudinal foot arch. As a result, the foot's load-bearing capacity is reduced, leading to overuse injuries such as back pain, patellofemoral pain, or medial tibial stress syndrome. The literature shows that people with flexible flat feet have disturbed foot and ankle kinematics during locomotor tasks. However, the current literature lacks insight into the kinetics of the foot joints (i.e., forces that cause joint movement) during both relatively simple tasks such as walking and running and more challenging tasks such as landing from a step. The recent development of multisegmental kinetic foot models allows for detailed information to be obtained regarding (mal)adaptive joint loading patterns in this population and address shortcomings in the current literature. In recent years, the small intrinsic foot muscles (IFM) have received more attention in the treatment of foot and ankle-related overuse injuries, such as plantar fasciitis, medial tibial stress syndrome, and Achilles tendinopathy. According to the "foot core" paradigm, the primary role of the intrinsic foot muscles is to support the medial foot arch. They contribute to the absorptive and generative capacity of the medial foot arch and work together with the plantar aponeurosis, ligaments, and extrinsic foot muscles. It is known that their strength and volume are reduced in people with flat feet. A randomized controlled trial will be planned in which participants with symptomatic flexible flatfeet will be allocated to either receiving foot core strengthening exercises or custom made foot orthotics therapy. An asymptomatic group with flexible flatfeet will serve as a control group and will not undergo any intervention. Primary objective 1: To evaluate changes in foot joint kinetics and kinematics and intrinsic foot muscle size following a foot core strengthening program in participants with symptomatic flexible flatfoot and whether this is different to the control therapy. Secondary objective 1: To evaluate changes in foot posture, foot muscle strength, psychological scores, pain and symptoms following a foot core strengthening program and whether these changes are different in comparison to the control therapy. Secondary objective 2: To evaluate changes in foot joint kinematics and kinetics and intrinsic foot muscle size between participants with asymptomatic and symptomatic flexible flatfoot.
Investigators
Nicolas Haelewijn
Physiotherapist, Master of Science
KU Leuven
Eligibility Criteria
Inclusion Criteria
- •For both asymptomatic and symptomatic flexible flatfoot:
- •Adults between 18 and 65 years of age, able to run at a self- selected low speed.
- •Physically active: min. 1h30 and max 6 h/week
- •Foot Posture Index \> 6 AND Navicular drop \> 5 mm
- •Informed consent (ICF) obtained
- •For asymptomatic flexible flatfoot:
- •For symptomatic flexible flatfoot:
- •Diagnosis made by a physician
- •ICF obtained
- •Symptomatic =
Exclusion Criteria
- •For both groups:
- •\< 18 years, \> 65 years
- •Any medical contraindication to physical exertion
- •Systemic diseases
- •Recent lower limb surgery (\< 6 months)
- •Lower limb osteosynthesis material
- •Pregnancy
- •Pacemaker
- •Leg length discrepancy \> 3 cm
- •Body Mass Index (BMI) \> 30kg/m²
Outcomes
Primary Outcomes
Change in lower limb joint angular velocities (degrees/second)
Time Frame: 8-week intervention period
Joint angular velocities are also assessed based on reflexive markers placed on anatomical landmarks. This outcome evaluates the rate of change of a certain joint angle over time. Joint angular velocities will be assessed of the multiple joints that constitute the lower limb (hip, knee, ankle, chopart, lisfranc and metatarsophalangeal) during walking, running and a single leg drop jump in the gait laboratory.
Change in joint moments
Time Frame: 8-week intervention period
Joint moments will be determined by coupling kinematic data (joint position and velocities) with plantar pressure data from a specially designed pressure plate (sampled at 200Hz, Footscan, dimension 0.5m x 0.4m, 4096 sensors, 2.8 sensors/cm², RsScan International, Olen, Belgium) embedded in the middle of the runway and placed on top of a force plate (sampled at 1000Hz, Advanced Mechanical Technology Inc., Watertown, MA, USA). Kinetic data will be assessed while walking, running and a single leg drop jump in the gait laboratory.
Change in lower limb joint angles (degrees)
Time Frame: 8-week intervention period
Joint angles will be measured based on the position of passive markers placed on participants' anatomical landmarks all over the lower limbs. The position of those markers will be tracked by 10 infrared high-speed cameras that surround the walkway (sampled at 100 Hertz (Hz) - type T-10, 1 megapixel, captures 10-bit grayscale using 1120 \* 896 pixels, Vicon Motion System Ltd, Oxford, Metrics, UK). The angular positions of the multiple joints that constitute the lower limb (hip, knee, ankle, chopart, lisfranc and metatarsophalangeal) will be assessed during walking, running, and single leg drop jump in the gait laboratory.
Change in foot muscle thickness
Time Frame: 8-week intervention period
The thickness of five intrinsic foot muscles (abductor hallucis, flexor digitorum brevis, flexor hallucis, quadratus plantae and abductor digiti minimi) and three extrinsic foot muscles (peronei, tibialis anterior and flexor digitorum longus) will be measured on images obtained using ultrasonography. To obtain those images, the investigators will scan the muscles in a longitudinal view.
Change in foot muscle cross-sectional area
Time Frame: 8-week intervention period
The area of five intrinsic foot muscles (abductor hallucis, flexor digitorum brevis, flexor hallucis, quadratus plantae and abductor digiti minimi) and two extrinsic foot muscles (peronei and flexor digitorum longus) will be measured on images obtained using ultrasonography. To obtain those images, the investigators will scan the muscles in a transversal view.
Secondary Outcomes
- Change in foot muscle strength(8-week intervention period)
- Change in navicular drop(8-week intervention period)
- Change in the FAOS questionnaire(8-week intervention period)
- Change in the OSPRO-YF questionnaire(8-week intervention period)
- Change in foot Posture Index(8-week intervention period)