Kinematic Analyses of the Thumb during Simulated Posteroanterior Glide Mobilization.

Meng-Tzu Hu,Ar-Tyan Hsu,Fong-Chin Su,Sharon Swartz

doi:10.1371/journal.pone.0161624

Abstract

ObjectiveThumb problems are common in some health professionals such as physical therapists. The purpose of this case-control study is to investigate the influence of clinical experience and different mobilization techniques on the kinematics of the thumb.MethodsTwenty-three participants without exposure to manual techniques (the Novice Group) and fifteen physical therapists with at least 3 years of orthopedic experience (the Experienced Group) participated. The kinematics of the thumb while performing 3 different simulated posteroanterior (PA) glide mobilization techniques on a load cell was monitored. These 3 techniques were: 1) unsupported, 2) with digital support and 3) with thumb interphalangeal joint supported by the index finger. The amount of forces exerted were 25% to 100% of maximum effort at 25% increments. The main effects of experience and technique on thumb kinematics were assessed.ResultsBoth experience and technique had main effects on the flexion/extension angles of the thumb joints. Experienced participants assumed a more flexed position at the carpometacarpal (CMC) joint, and the novice participants performed with angles closer to the neutral position (F = 7.593, p = 0.010). Participants’ metacarpophalangeal (MCP) joints were in a more flexed position while performing PA glide with thumb interphalangeal (IP) joint supported by the index as compared to the other two techniques (p < .001).ConclusionsNegative correlations were generally obtained between the sagittal plane angles of adjacent thumb joints during mobilization/manipulation. Therapists are recommended to treat patient with more stable PA glide mobilization techniques, such as PA glide with thumb interphalangeal joint supported by the index finger, to prevent potential mobilization-related thumb disorders.

Highlights

The specific anatomical structural arrangement of the thumb provides the human hand with the unique capacity of a powerful grip as well as precision object manipulation [1]
Thumb Kinematics during Posteroanterior Mobilization with more stable PA glide mobilization techniques, such as PA glide with thumb interphalangeal joint supported by the index finger, to prevent potential mobilization-related thumb disorders
In subjects with hypermobility syndrome, proprioceptive deficiency may play a part in thumb kinematics as it has been reported in the proximal interphalangeal joint of the index [14]

Summary

Introduction

The specific anatomical structural arrangement of the thumb provides the human hand with the unique capacity of a powerful grip as well as precision object manipulation [1] Manual therapy procedures, such as joint mobilization, manipulation and soft tissue techniques frequently involve complicated and strenuous loading of the thumb joints. The authors suspected that the deviation of the thumb position during large force application might explain the complaints made by young physiotherapy graduates found in Cromie’s study [8] Factors, such as individual experience and different techniques used to complete the task may result in differential upper extremity kinematics [9]. The purposes of this study were to investigate the influence of clinical experience, joint laxity features and different PA glide mobilization techniques on thumb kinematics while performing PA glide mobilization with the thumb in a group of physical therapists and their novice counterparts. We hypothesized that the alignment of the thumb would differ with clinical experience, joint laxity features, and different PA glide techniques

Methods

Results

Conclusion