The effect of induced joint restriction on plantar pressure during gait - a pilot study

The effect of calcaneus and metatarsal head offloading insoles on healthy subjects' gait kinematics, kinetics, asymmetry, and the implications for plantar pressure management: A pilot study

BACKGROUND

The global number of people with diabetes is estimated to reach 643 million by 2030 of whom 19-34% will present with diabetic foot ulceration. Insoles which offload high-risk ulcerative regions on the foot, by removing insole material, are the main contemporary conservative treatment to maintain mobility and reduce the likelihood of ulceration. However, their effect on the rest of the foot and relationship with key gait propulsive and balance kinematics and kinetics has not been well researched.

PURPOSE

The aim of this study is to investigate the effect of offloading insoles on gait kinematics, kinetics, and plantar pressure throughout the gait cycle.

METHODS

10 healthy subjects were recruited for this experiment to walk in 6 different insole conditions. Subjects walked at three speeds on a treadmill for 10 minutes while both plantar pressure and gait kinematics, kinetics were measured using an in-shoe pressure measurement insole and motion capture system/force plates. Average peak plantar pressure, pressure time integrals, gait kinematics and centre of force were analysed.

RESULTS

The average peak plantar pressure and pressure time integrals changed by -30% (-68% to 3%) and -36% (-75% to -1%) at the region of interest when applying offloading insoles, whereas the heel strike and toe-off velocity changed by 15% (-6% to 32%) and 12% (-2% to 19%) whilst walking at three speeds.

CONCLUSION

The study found that offloading insoles reduced plantar pressure in the region of interest with loading transferred to surrounding regions increasing the risk of higher pressure time integrals in these locations. Heel strike and toe-off velocities were increased under certain configurations of offloading insoles which may explain the higher plantar pressures and supporting the potential of integrating kinematic gait variables within a more optimal therapeutic approach. However, there was inter-individual variability in responses for all variables measured supporting individualised prescription.

Static Plantar Pressure under Different Conditions in Children with Surgically Treated Unilateral Slipped Capital Femoral Epiphysis

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is the most common hip disease during infancy and adolescence. Our study aimed to analyze static plantar pressure in children with surgically treated unilateral SCFE.

METHODS

Twenty-two children with right SCFE with in situ fixation with one percutaneous screw were assessed by PoData plantar pressure analysis under three different conditions (open eyes, eyes closed, and head retroflexed).

RESULTS

The total foot loading was significantly higher on the unaffected limb compared with the affected one for all the three testing conditions (p < 0.05). When assessing the differences between testing conditions, there were no significant differences for the right and left foot loadings, or for the three sites of weight distribution, except for the right fifth metatarsal head (lower loading in eyes-closed condition in comparison to eyes open, p = 0.0068), left fifth metatarsal head (increased loading in head-retroflexed condition in comparison to eyes open, p = 0.0209), and left heel (lower loading in head-retroflexed condition in comparison to eyes open, p = 0.0293).

CONCLUSION

Even after a successful surgical procedure, differences in foot loading can impact the postural static activities in different conditions (natural eyes-open, eyes-closed, or head-retroflexed posture).

The pressure time integral: An underused, clinically significant parameter as a determinant of neuropathic ulceration in diabetes

BACKGROUND

The purpose of this study was to evaluate plantar pressure dynamics in the occurrence of active diabetic neuropathic ulceration (DNU) and any changes in loadings occurring in individuals with a history of diabetic neuropathic ulceration (DHNU). Since current gold standard offloading strategies are not producing desirable healing outcomes and optimum ulcer prevention, this study aimed to better understand the effect of diabetic peripheral neuropathy (DPN) and ulceration on mean peak plantar pressure (MPPP) and pressure-time integral (PTI) changes.

RESEARCH QUESTION

Is there a redistribution of plantar pressure during gait in the presence of active and history of diabetic neuropathic ulceration?

METHODS

A prospective, cross-sectional study was conducted, in which, eighty adult participants were divided into four groups, namely, the DM, DPN, DNU and DHNU groups. Participants were instructed to walk barefoot over a Tekscan HR Mat™ at self-selected speed. MPPP and PTI data were analysed under five forefoot anatomical landmarks and compared between individuals with and without active neuropathic ulceration.

RESULTS

Minimal MPPP significant changes were observed between ulcerated and non-ulcerated groups, however, PTI values were significantly increased in the ulcerated groups under all plantar ulceration regions. No significant plantar pressure differences were observed between the DNU and DHNU groups. Logistic regression tests demonstrated that as PTIs under the hallux increase, the likelihood of an individual living with DPN developing ulceration increases.

SIGNIFICANCE

A significant increase in PTI values in the presence of ulceration highlights the importance of evaluating the duration of loads under forefoot regions during gait rather than just focusing on the magnitude of pressures during ulcer management and prevention. Moreover, results show that PTI values remain high in the presence of a history of neuropathic ulceration, possibly demonstrating the value of PTI as a clinical tool over MPPP in the assessment of the high-risk diabetic foot.