Elsevier

Gait & Posture

Volume 45, March 2016, Pages 103-109
Gait & Posture

Biomechanical risk factors for tripping during obstacle—Crossing with the trailing limb in patients with type II diabetes mellitus

https://doi.org/10.1016/j.gaitpost.2016.01.010Get rights and content

Highlights

  • Diabetes mellitus reduced trail toe-obstacle clearance, increasing tripping risk.

  • Reduced trailing knee flexion and hip adduction are risk factors for tripping.

  • Increased ankle plantar flexor effort is needed in diabetes mellitus.

Abstract

People with type II diabetes mellitus (DM) are at a high risk of falling especially during more challenging locomotor tasks such as obstacle-crossing. The current study aimed to identify the risk factors for tripping in these patients during trailing-limb obstacle-crossing. Fourteen patients with type II DM with or without mild peripheral neuropathy (PN) and 14 healthy controls walked and crossed obstacles of three different heights while their motion data were measured using a motion capture system and two forceplates. The DM group was found to cross obstacles with significantly reduced trailing toe clearance (p < 0.05), increasing the probability of the foot hitting the obstacle, and thus the risk of tripping. This altered end-point control was associated with significantly reduced knee flexion and hip adduction of the trailing swing limb (p < 0.05), as well as significantly increased ankle plantarflexor moments in the leading stance limb (p < 0.05). Therefore, reduced knee flexion and hip adduction of the swing limb are identified as risk factors for tripping during obstacle-crossing. Increased mechanical demands on the ankle plantarflexors suggest that weakness of these muscles may further reduce the already compromised performance of obstacle-crossing in these patients. The current results showed that obstacle-crossing can be used to detect gait deviations and to identify the associated risk of tripping in patients with type II DM without or at an early stage of PN.

Introduction

Obstacle negotiation during gait is an inevitable part of daily living. Failure to cross obstacles as a result of loss of balance or tripping over obstacles may lead to falls with serious consequences [1]. Since the risk of falling increases linearly with the number of risk factors, obstacle-crossing in patients with systemic diseases may result in an increased incidence of falling [2]. While developing fall prevention strategies, previous motion analysis studies have identified the biomechanical risk factors and mechanisms of falling during obstacle-crossing in traumatic brain injuries [3] and osteoarthritis [4]. However, studies on diabetes mellitus (DM) during obstacle-crossing have been limited [5], despite the fact that patients with type II DM are at a high risk of falling [6], those aged from 45 to 65 years being the most at risk [7].

Gait and balance were found to be independently associated with a heightened risk of falling in patients with DM [8]. Degraded gait performance [9], [10], [11] and postural control [12] have been observed in patients with no or minimal diabetic peripheral neuropathy (PN), with impaired proprioception of the distal joints [5] and degraded ankle dorsiflexor and plantarflexor strength [13]. This suggests that patients with DM would be at risk of falling long before loss of sensation to the feet is observed [14]. Therefore, it is essential to identify gait deviations and the associated risk of falling in patients with DM before PN is diagnosed.

An appropriate swing toe-clearance and minimum stability of the stance limb is essential for a safe and successful obstacle-crossing. Therefore, variables such as toe-clearances above the obstacle and the associated kinematics and kinetics of the lower extremities have been used to identify the biomechanical strategies during obstacle-crossing and the associate risk factors for falling [15]. Previous studies showed that toe clearances of the trailing limb were smaller than those of the leading limb [16], suggesting that an increased risk of tripping owing to toe-obstacle contact may occur when the trailing limb is crossing. This is because the trailing limb has a shorter time and distance for preparing for a safe crossing with sufficient clearance as a result of the placement of the trailing foot on the floor being closer to the obstacle before crossing [17]. The joint kinematics and kinetics of both limbs associated with the observed toe-clearance are important for identifying the biomechanical risk factors for falling. Liu et al. reported that patients with DM increased ankle dorsiflexion and plantarflexor moments of the trailing stance limb with reduced leading toe-clearance during obstacle-crossing with the leading limb [18]. However, similar information during trailing limb crossing is still not available.

To address this issue, motion data from patients with type II DM with no or mild PN were obtained when crossing obstacles of different heights with the trailing limb in order to investigate the biomechanical strategies adopted and the possible risk factors for falling. It was hypothesized that the patients would exhibit altered gait patterns and end point control as compared to healthy controls during the obstacle-crossing tasks.

Section snippets

Subjects

Movement data from fourteen patients with type II DM (seven females and seven males; age: 55.1 ± 8.1 years, height: 165.0 ± 6.8 cm, mass: 66.3 ± 11.6 kg) and fourteen healthy controls (seven females and seven males; age: 52.9 ± 5.7 years, height: 156.4 ± 8.9 cm, mass: 57.6 ± 8.2 kg) when crossing obstacles of different heights were collected in a previous study [18] with informed written consent as approved by the Institutional Research Board. The patients had to meet the following inclusion criteria: (a) aged

Results

Two subjects from the DM group were excluded from the analysis because their tibial tuberosity and toe markers on the trailing limb were not captured around the time when the trailing toe was supposed to be above the obstacle. Therefore, the results presented here are from 12 subjects in the DM group and 14 healthy controls. During the experiment, none of the subjects hit the obstacle with the leading limb. For the trailing limb, 2 contacts out of 218 trials (about 0.9%) were registered in the

Discussion

The current study aimed to investigate the biomechanical strategies and risk factors for tripping during obstacle-crossing with the trailing limb in patients with type II DM with no or mild PN. The DM group was able to cross obstacles successfully with the trailing limb but with significantly reduced toe clearance, primarily owing to significantly reduced flexion of the swing knee and reduced adduction of the swing hip. This altered end-point control was also associated with increased

Conclusions

Patients with mild type II DM displayed reduced toe-clearance of the trailing limb when crossing obstacles of different heights, indicating an increased risk of tripping. Reduced knee flexion and hip adduction of the swing limb have been identified as risk factors for tripping during obstacle-crossing with the trailing limb. Increased mechanical demands on the ankle plantarflexors were also needed in these patients. Obstacle-crossing can be used to detect gait deviations and to identify the

Conflict of interest

None.

References (30)

Cited by (20)

  • Inter-joint coordination during obstacle crossing in people with diabetic neuropathy

    2020, Journal of Biomechanics
    Citation Excerpt :

    Reduced toe-obstacle clearance in the leading limb and increased dorsiflexion, ankle plantar flexor moment, and knee flexor moment in the trailing stance limb in the DM patients as compared to healthy individuals has been reported (Liu et al., 2010). Moreover, patients with DM had decreased trailing toe clearance, knee flexion and hip adduction, and increased ankle plantar flexor moments in the leading stance limb (Hsu et al., 2016). These studies suggest that patients with DM are at higher risk of tripping over obstacles.

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