Original research
Evaluation of a Task-Based Intervention After Tendon Transfer to Restore Lateral Pinch

https://doi.org/10.1016/j.apmr.2015.12.032Get rights and content

Abstract

Objective

To quantify changes in pinch force and brachioradialis (BR) activation after a task-based training program designed to improve pinch force after BR to flexor pollicis longus (FPL) transfer.

Design

One-group repeated-measures design compared pinch force and BR activation pre- and posttraining. Significant differences were tested with Wilcoxon signed-rank tests for pairwise comparisons at the P≤.05 level.

Setting

Testing occurred in a Veterans Affairs Medical Center research laboratory and training was in a home setting.

Participants

Participants with cervical spinal cord injury (SCI) and previous BR to FPL transfer were enrolled in the study (N=8). Six patients completed the training program and posttraining measures.

Interventions

The 10-week training was a home program that included novel activities to increase BR activation and practice producing pinch force in a variety of upper limb postures. Participants were provided with the task-based training equipment and instructed to practice 3 times per week.

Main Outcome Measures

Fine-wire electromyography of the transferred BR was recorded in maximum effort pinch force (N). Secondary measures included the strength and activation of the antagonist elbow extensor.

Results

Pinch force increased 3.7N (.38kg) and BR muscle activation increased 10% (P≤.05) after the training. There was no increase in elbow extension strength, but participants with previous posterior deltoid to triceps transfer achieved greater activation of the antagonist elbow extensor.

Conclusions

The findings from this pilot study suggest that outcomes of tendon transfer and conventional therapy can be improved for patients with chronic cervical SCI.

Section snippets

Participants

Participants with chronic cervical SCI and previous BR to FPL transfer were recruited. The International Classification for Surgery of the Hand in Tetraplegia was used to determine if an individual would benefit from BR to FPL surgery.1, 2 All participants were previously evaluated by the same surgeon (V.R.H.) and were in International Classification for Surgery of the Hand in Tetraplegia group ≥2 (manual muscle test grade 4 BR and grade 4 or 5 wrist extension strength). If BR to FPL transfer

Participants

Eight participants were admitted to the study to participate in the 10-week training program. All of the participants had chronic cervical SCI with complete injuries and a previous BR to FPL tendon transfer to restore pinch strength. From the medical record at the time of admission, 7 of the participants were classified with C5-7 level injuries. One participant (participant 6) was classified with a C4 injury, but met the criteria for BR to FPL surgery according to the International

Discussion

The task-based home training was effective for improving pinch force relative to individual pretraining measures. Recognizing patients who may benefit from the training should be determined on an individual basis because of the individual variability in pinch strength observed across participants. Pretraining pinch force in the range of 3N suggests that force is produced using passive tenodesis,9 and the transferred BR may not be active in pinch or surgical revision may be indicated (eg,

Conclusions

The outcome of BR to PFL tendon transfer, measured by pinch force and activation of the transferred BR, can be improved for individuals with chronic SCI, even many years after they have been discharged. There was significant gain of 3.7N of pinch force and a 10% increase in BR activation for participants who adhered to the novel training program described in this pilot study. There were no adverse effects from participating. Implementing the training program prior to discharge and increasing

Suppliers

  • a.

    LABView; National Instruments.

  • b.

    ATI Industrial Automation.

  • c.

    MA-300 cabled system; Motion Lab Systems, Inc.

  • d.

    MATLAB; MathWorks.

  • e.

    JMP statistical program; SAS Institute.

  • f.

    Theraputty; Patterson Medical-Sammons Preston.

  • g.

    Pace Weights; Pace Weights.

  • h.

    MiniMeds; FitBALL.

  • i.

    Baseline Hydraulic 50-lb Pinch Gauge; Patterson Medical-Sammons Preston.

Acknowledgments

We thank the clinical staff of the Spinal Cord Injury Service at the VA Palo Alto Health Care System, who were instrumental for recruitment and coordinating follow-up visits. We also thank volunteer Dave Izant, who was responsible for building the manipulation boards and modifications to the pinch pins so that those individuals with low forces could participate. We thank Jeffrey Jaramillo, DPT, who provided critical review of the manuscript.

Cited by (5)

The research described here was supported by the Department of Veterans Affairs, Veterans Health Administration, Rehabilitation Research and Development Service, Career Development Award B6857 and B0583-P, M. Elise Johanson, VA Palo Alto Health Care System, Research Service.

Publication of this article was supported by the American Congress of Rehabilitation Medicine.

Disclosures: none.

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