The Effect of Load Carriage on Upper Limb Performance

Purpose: Quantify the relationship between brachial plexus deformations caused by backpack carriage and upper extremity performance.

Significance of expected results:

The study will allow to quantify the effect of load carriage on both neural and vascular function parameters.

Study plan The effect of nerve strain on neural function: based on the strains obtained for each load from computational simulation, and from animal studies published in the literature, the expected neural function, (e.g., motor and sensory) dysfunction will be estimated.

Following signing an informed consent form, 12 young adult subjects (18-35 years) will don a military backpack loaded with 25-40 kg. Each volunteer will undergo the following test at baseline, following 45 min exposure, and following 15 min of recovery:

1. Index finger microvascular flow will be measured by photoplethysmography (PPG).
2. Sensory measurement at the finger; Light touch threshold will be measured by mechanical stimulation that will be applied using Von Frey Filaments of the Semmes-Weinstein Monofilament (SWM) type.

3. Forearm thermal sensation threshold; As a measure of sensory function in the forearm, cold and warm sensation thresholds will be measured with a computerized quantitative thermal sensory device.

   Immediately following the 45 min loading exposure, the fine motor function of the index finger will be tested by the following procedures (in an unloaded condition):

4. Index finger motor function; Force application profile during a trigger press will be measured using a force sensor located on a trigger of a dummy weapon simulator. Force application rate, peak force, and press-to-press peak force variability will be measured based on 10 trigger presses.
5. Accuracy of force application; Will be evaluated by the simulated shot accuracy, horizontal displacement (X) and vertical displacement (Y).
6. Subjective parameters; in all time points, the volunteers will be asked to rate their level of pain sensation intensity (VAS sensory) and degree of unpleasantness (VAS affective) in the shoulders and other load bearing sites, as well as ratings of perceived exertion (RPE). All subjective parameters will be assessed using visual analogue scales.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: load carriage

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

Healthy medical status, fit (regular physical activity > 3 times weekly) men Previous experience with heavy backpack carriage Age: 18-35

Exclusion Criteria:

Heavy load carrying activity in the past 48 hr

Known diseases or medical conditions that may interfere with the study, of:

Musculoskeletal system Nervous system Cardiovascular system Vascular disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Healthy men; each individual will serve as his own control by comparing baseline values to post intervention values	Other: load carriage

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Neural performance of upper limb as measured by light touch sensitivity treshold	1 hour
Neural performance of upper limb as measured by Thermal sensation treshold	1 hour
Vascular performance of upper limb as measured by photoplethysmography of the index finger	1 hour

Secondary Outcome Measures

Outcome Measure	Time Frame
Motor function of upper limb as measured by force application of the index finger	1 hour

Collaborators and Investigators

• Sponsor: Sheba Medical Center
• Collaborators: Tel Aviv University

Study record dates

Study Major Dates

• Study Start: January 1, 2015
• Primary Completion (Actual): August 1, 2016
• Study Completion (Actual): August 1, 2016

Study Registration Dates

• First Submitted: January 6, 2015
• First Submitted That Met QC Criteria: January 13, 2015
• First Posted (Estimate): January 14, 2015

Study Record Updates

• Last Update Posted (Actual): May 2, 2017
• Last Update Submitted That Met QC Criteria: May 1, 2017
• Last Verified: May 1, 2017

More Information

Terms related to this study

• Keywords: Sports Medicine; Neurology
• Other Study ID Numbers: 1593-14-SMC