Søren Kaalund

Video based analysis of dynamic midfoot function and its relationship with Foot Posture Index scores

INTRODUCTION Various studies have demonstrated significant as well as non-significant relationships between static evaluation of foot posture and injury likelihood. Therefore, the relationship of static and dynamic measures needs to be established as in clinical settings time consuming dynamic methods are often not feasible. PURPOSE Assess reliability of a new method to quantify midfoot movement and validate the use of Foot Posture Index (FPI) classification as predictor of dynamic foot function during walking. METHOD Foot type was classified using FPI in 280 randomly selected adult participants (mean age 43.4 years). A Video Sequence Analysis (VSA) system was used to quantify midfoot kinematics during walking. Navicula drop (DeltaNH) and minimal navicula height (NHL) were compared with FPI. RESULTS The Intraclass Correlation Coefficients (ICC) for DeltaNH and NHL ranged from 0.65 to 0.95 with a coefficient of repeatability of 1.4 mm for DeltaNH and 4.5 mm for NHL. System precision was estimated at 0.99 mm for DeltaNH and 3.18 mm for NHL. DeltaNH was significantly positively correlated with FPI scores while NHL decreased with increasing FPI. However, the FPI model predicted only 13.2% of the variation in DeltaNH and 45% of the variation in NHL during walking (p<0.001). CONCLUSION The VSA was proven as a reliable and precise method to quantify midfoot kinematics. FPI scores and individual components of the FPI show strong statistical relationships to dynamic measures but individual predictions remain questionable. Dynamic midfoot measures are recommended for clinical foot assessments.

High-load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12-month follow-up

The aim of this study was to investigate the effectiveness of shoe inserts and plantar fascia‐specific stretching vs shoe inserts and high‐load strength training in patients with plantar fasciitis. Forty‐eight patients with ultrasonography‐verified plantar fasciitis were randomized to shoe inserts and daily plantar‐specific stretching (the stretch group) or shoe inserts and high‐load progressive strength training (the strength group) performed every second day. High‐load strength training consisted of unilateral heel raises with a towel inserted under the toes. Primary outcome was the foot function index (FFI) at 3 months. Additional follow‐ups were performed at 1, 6, and 12 months. At the primary endpoint, at 3 months, the strength group had a FFI that was 29 points lower [95% confidence interval (CI): 6–52, P = 0.016] compared with the stretch group. At 1, 6, and 12 months, there were no differences between groups (P > 0.34). At 12 months, the FFI was 22 points (95% CI: 9–36) in the strength group and 16 points (95% CI: 0–32) in the stretch group. There were no differences in any of the secondary outcomes. A simple progressive exercise protocol, performed every second day, resulted in superior self‐reported outcome after 3 months compared with plantar‐specific stretching. High‐load strength training may aid in a quicker reduction in pain and improvements in function.

Exercise therapy and custom-made insoles are effective in patients with excessive pronation and chronic foot pain—A randomized controlled trial

BACKGROUND Excessive foot pronation is a causal mechanisms described in relation to injuries of the lower extremities. Evidence to support an effective treatment is insufficient. OBJECTIVE To investigate the effect of exercise and custom-made insoles to patients with excessive pronation and chronic pain conditions in the foot at short and long term follow-up. METHODS Single blinded Randomized Controlled Trial with 80 subjects randomized: (1) Standard Intervention, (2) Insole, (3) Exercise, and (4) Insole+Exercise. Exercise - 12 week supervised program. Insoles - individually molded and posted. Pain was measured during walking, resting and running. Static and dynamic foot postures were measured as calcaneal angle, navicular drift, drop and height. RESULTS The average duration of foot pain was 7.3 years. There was a significant pain reduction during walking within all groups at 4 and 12 months follow-up. No differences were seen between groups in any of the pain parameters. Weak correlations between changes in pain and foot postures were observed at baseline and one-year follow-up. CONCLUSION A significant pain reduction was seen in all groups, none of the treatment modalities seem to be superior with the number of patients included. Compliance in the standard intervention group was a concern at 12 months.

Dynamic midfoot kinematics in subjects with medial tibial stress syndrome.

BACKGROUND Medial tibial stress syndrome (MTSS) is a common diagnosis. Several studies have demonstrated that excessive static navicular drop (ND) is related to the diagnosis. However, no studies have yet investigated ND and the velocity of ND during dynamic conditions. The aim of this study was to evaluate ND characteristics in patients with MTSS in dynamic and static conditions. METHODS In a case-control study, 14 patients diagnosed as having MTSS were included from an orthopedic outpatient clinic. A control group consisting of 14 healthy participants was matched regarding age, sex, and typical sporting activity. Navicular drop was evaluated during treadmill walking by a two-dimensional video analysis. Static foot posture, static ND, dynamic ND (dND), and velocity of dND were compared. RESULTS The two groups were comparable in relation to age, sex, height, weight, and foot size. No significant difference was found in static foot posture. Static ND showed a mean difference of 1.7 mm between the groups (P = .08). During treadmill walking, patients with MTSS had, on average, a 1.5-mm-larger dND (P =.004) and a 2.4-mm/sec-larger mean velocity of dND (P = .03). CONCLUSIONS Patients with MTSS display a larger ND and a higher ND velocity during treadmill walking. Increased ND velocity may be important to this condition. Future studies should include velocity of dND to investigate the mechanisms of dND in relation to overuse injuries.

Pressure Pain Sensitivity Changes After Use of Shock-Absorbing Insoles Among Young Soccer Players Training on Artificial Turf: A Randomized Controlled Trial

STUDY DESIGN Prospective, randomized, controlled single-blind intervention trial. OBJECTIVES Shock-absorbing insoles (SAIs), compared with usual insoles, were hypothesized to result in larger increases in pressure pain threshold (PPT) after 3 weeks of use. BACKGROUND Shock-absorbing insoles can decrease self-reported pain among young soccer players training on artificial turf. However, nothing is known about the underlying changes in pain sensitivity assessed by PPT. Methods Seventy-five players were included from the youth teams of under 15, under 17, and under 19 years of age, playing for the Aalborg Boldspilklub (AaB) professional sports club. After a randomization stratified by team and age, players were divided into 2 groups, one that received SAIs and a control group that used their usual insoles. Assessments were made in both groups after 3 weeks of training on artificial turf (baseline) and 3 weeks later (follow-up). The primary outcome was change in PPTs from baseline to follow-up, with PPTs measured over 13 locations on the plantar surface of the foot, leg, and low back of the nonpreferred kicking leg. RESULTS A significantly larger increase was found in PPTs from baseline to follow-up for the SAI group compared with the control group (mean difference, 62 kPa; 95% confidence interval [CI]: 40, 85 kPa). The PPTs increased significantly more among the SAI group compared with the control group (P<.05) for the abductor digiti minimi (mean difference, 82 kPa; 95% CI: 6, 157 kPa), tibialis anterior (mean difference, 125 kPa; 95% CI: 20, 230 kPa), medial gastrocnemius (mean difference, 83 kPa; 95% CI: -6, 171 kPa), and erector spinae (mean difference, 86 kPa; 95% CI: -17, 188 kPa). CONCLUSION The use of SAIs resulted in increased PPTs after 3 weeks of training on artificial turf compared with controls, suggesting a protective role of SAIs in pressure sensitivity and pain perception.

The predictive value of the foot posture index on dynamic function

Keenan et al [1] identified the six-item version of the Foot Posture Index (FPI) as a valid, simple and clinically useful tool. The model combines measures of the standing foot posture in multiple planes and anatomical segments. It provides an alternative to existing static clinical measures when dynamic measures are not feasible. Redmond et al. [2] found the model able to predict 41% of the variation in the complex rotation of the ankle joint, representing inversion/eversion, during midstance of walking. To our knowledge no studies have been published on the relationship between the FPI and the movement of the midfoot during walking. The purpose of this study was to investigate the use of FPI classification as a predictor for dynamic midfoot kinematics during walking.

Effects of shock-absorbing insoles during transition from natural grass to artificial turf in young soccer players: a randomized controlled trial

BACKGROUND Playing soccer on artificial turf can provoke pain in young players. Using shock-absorbing insoles (SAIs) can result in decreased pain perception. We sought to investigate the pain and comfort intensity experienced during the switch from natural grass to third-generation artificial turf and with the use of SAIs on artificial turf during training in young soccer players. METHODS In a prospective randomized controlled study, 75 players were included from the youth teams of U15, U17, and U19. Pain intensity and comfort were assessed after training on only grass turf for 3 months. Randomization stratified by team level and age was performed; the intervention group received SAIs, and the control group used their own insoles. Assessments were repeated after 3 weeks on artificial turf (baseline) and 3 more weeks (follow-up) on artificial turf with SAIs/usual insoles. RESULTS Pain intensity increased and comfort decreased significantly after 3 weeks of training on artificial grass compared with natural grass (P < .05). The addition of SAIs resulted in significantly reduced pain intensity compared with the usual insoles (P < .05). CONCLUSIONS The switch to artificial turf is associated with less comfort and more pain during training in young soccer players. The use of SAIs led to lower pain intensity, highlighting a protective role of the insoles after 6 weeks of training on artificial turf.