Quantifying the Trainability of Peripheral Nerve Function in Young and Older Adults.
Phase: NA
Conditions: Nerve Degeneration, Healthy Aging
Sponsor: Oklahoma State University

Study Title: 
Quantifying the Trainability of Peripheral Nerve Function in 
Young and Older Adults.  
 
Study Registration  
Number:  
IRB-22-270 
 
 
Principal Investigator   
Jason M. DeFreitas, PhD  
 
Professor and Chair of Exercise Science  
 
Neural Health Research Laboratory  
 
Syracuse University, Syracuse, NY, United States  
 
(Previously at Oklahoma State University) 
 
NCT number  
 
N/A 
 
Version   
 
 
2.0  
 
Date 
 
 
 
9/17/2024 
 
Author  
 
 
JoCarol E. Shields, PhD  
 
 
 
 
 
Postdoctoral Research Assistant 
 
 
 
 
Neural Health Research Laboratory  
 
Syracuse University, Syracuse, NY, United States  
 
(Previously at Oklahoma State University) 
 
 
 
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
 
 
 

SIGNATURE PAGE  
 
 
 
AUTHOR:  
Name: Jason M. DeFreitas 
 
 
Professor and Chair  
 
 
 
 
 
 
 
 
 
 
 
Name: JoCarol E. Shields 
 
 
Postdoctoral Research Assistant   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Abbreviations  
 
SAP 
 
Statistical Analysis Plan 
NCV  
Nerve Conduction Velocity  
nCSA  
Nerve Cross-Sectional Area 
FDS 
 
Flexor Digitorum Superficialis 
ANOVA 
Analysis of Variance 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
1. Introduction  
 
The primary objective of this study was to quantify the effects of hand grip resistance 
training on nerve function in young and older adults (primary aim) and to determine if 
training affects nerve cross-sectional area, maximal hand grip strength, and hand motor 
dexterity (secondary aims).  
 
The statistical analysis plan (SAP) provides details of the statistical methods used during the 
analyses of data collected within the scope of IRB-22-270 and was prepared in accordance to 
IRB-22-270 (version 1; 9-9-2024).  
 
2. Overview & Objectives of Study Design  
This study consisted of four arms, first separated by age based on our target ranges (young = 
18-35 yrs old, and older = 60+ yrs old), and then pseudo-randomly assigned to either the 
intervention group or control group. Conditions of inclusion were apparently healthy adults 
between the ages of 18 – 100 years old. Individuals with any of the following exclusion 
criteria were not permitted to participate: 1.) If you have been notified by a physician to 
refrain from exercise due to cardiovascular issues, 2.) Known orthopedic or neuromuscular 
limitations or illness of the upper extremities, 3.) Known neuromuscular disorders, and 4.) 
Individuals that were experiencing a fever (> 100.4° F) or had identified as symptomatic on 
the COVID-19 screening questionnaire were not permitted to participate. 
 
Participants assigned to the intervention group performed bilateral hand grip resistance 
training 3×/week for 4 weeks using a specialized hand-grip kit provided to them. This 
included Arm 1 (Young Training Group) and Arm 3 (Older Training Group). Participants 
were provided with pictures and instructions for each exercise upon completion of visit 1. 
Those assigned to the control group were asked to maintain normal daily activities 
throughout the duration of the four weeks. This included Arm 2 (Young Control Group) and 
Arm 4 (Older Control Group).  
 
Laboratory testing visits were performed at two time points: visit 1 (before the intervention) 
and visit 2 (after four weeks) at which nerve conduction velocity, nerve cross-sectional area, 
maximal hand grip strength, and hand motor dexterity were measured.  
 
3. Sample Size Justification  
Power calculations indicated that a sample size of  > 16 was sufficient power (Cohen’s d = > 
- 0.80) with the alpha set at 0.05 (G*Power v. 3.1, Dusseldorf, Germany). Therefore, 
recruitment of 80 participants pseudo-randomly assigned to 1 of 4 groups (control vs 
training: young; control vs training: old) should ensure a large enough sample size (>16) to 
report alterations in nerve conduction velocity as a result of resistance training.  
 
4. Aims and Objectives  
To quantify the effects of resistance training on nerve conduction velocity in young and older 
adults and to determine if age affects nerve plasticity in response to training. 
 

5. Outcomes  
This section will present the outcomes investigated to answer the study aims and objectives. 
Analyses are described in section 6 analysis.  
 
5.1 Primary Outcome  
Nerve conduction velocity (NCV) of the Flexor Digitorum Superficialis (FDS) muscle. It 
was measured at visit 1 and visit 2 (four weeks apart).  
 
5.2 Secondary Outcomes  
• Nerve cross-sectional area (nCSA). 
• Maximal hand grip strength (kg) 
• Hand motor dexterity (time, in seconds, to task completion) 
 
Other laboratory parameters  
n/a 
 
5.3 Safety Outcomes  
Adverse events  
If adverse events occurred, adverse events were reported at each visit.  
 
6. Analyses  
All statistical analyses were performed using SPSS Version 26 (IBM, Armonk, NY,  
USA).  Two four-way mixed factorial ANOVA model’s (age [young vs old] × group [training 
vs. control] × time [pre vs. post] × limb [left vs. right]) were conducted to determine changes 
in NCV, nCSA, max strength, and dexterity. If warranted, dependent paired samples t-test 
were run. An alpha level of 0.05 was used for all comparisons.