The Effects of Finger Extensor Training on Climbing Performance Compared With Traditional Flexor Training

NCT07414862 | Active Not Recruiting

• 1 other identifier: 202532
• Study Type: interventional
• Target: 36
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study, is to assess climbing performance metrics that include max strength testing on a rock climbing hangboard, maximum grip strength, assessment of pain and function using the DASH (disability of the arm, shoulder and hand), and maximum flexor strength and maximum extensor strength in climbers who perform a traditional finger training protocol compared to climbers who train both traditional flexor training protocol and extensor tendons.

Conditions

Healthy Adult

Outcome Measures

Primary Outcomes (3)

• Maximal Finger Extension Strength (MES)

  Maximum isometric finger extension force for digits 2-5 measured using a VALD strain gauge system with finger loops positioned over the middle phalanx. Three 5-second trials per hand with 20 seconds rest; best of three recorded for each hand.

  Baseline (pre-training), 3 weeks, and 7 weeks (post-training)

• Maximal Finger Flexion Strength (MFS) on Hangboard

  Maximal added load (or total load) for a 7-second hang on a 30 mm hangboard edge using a standardized half/open crimp position. Load increased until participant cannot maintain the full 7 seconds; maximal successful load recorded.

  Baseline (pre-training), 3 weeks, and 7 weeks (post-training)

• Finger Stamina and Endurance /Time Under Tension (TUT) at 80% of MFS

  Stamina assessed as total time under tension while maintaining 80% of calculated maximal finger flexion strength using a Tindeq device and a 20 mm fingerblock. Endurance will be measured by calculating critical force at the completion of the test. Participants alternate 7-second work and 3-second rest cycles while attempting to maintain 80% target force for as many repetitions as possible to calculate stamina (up to 24 cycles). Critical Force will be calculated for each hand at completion of 24 cycles to measure endurance.

  Baseline, 3 weeks, and 7 weeks

Secondary Outcomes (2)

• Disabilities of the Arm, Shoulder and Hand (DASH) Score

  Baseline, 3 weeks, and 7 weeks

• Finger Flexion-to-Extension Strength Ratio

  Baseline, 3 weeks, and 7 weeks

Other Outcomes (1)

• Change in Maximal Finger Flexion and Extension Strength

  Baseline to 7 weeks

Study Arms (3)

Maximum Flexor Strength (MFS)

EXPERIMENTAL

Participants assigned to the Maximum Flexor Strength (MFS) group will perform a traditional finger flexor hangboard training protocol twice weekly for six weeks. Training is performed at 70% of maximal finger flexion strength using a standardized work-to-rest ratio. Participants will complete pre-, mid-, and post-intervention testing of grip strength, finger flexion strength, finger extension strength, finger endurance, and self-reported upper extremity function

Other: Traditional Hangboard Protocol

Maximum Extensor Strength (MES)

EXPERIMENTAL

Participants assigned to the Maximum Extensor Strength (MES) group will perform a traditional finger flexor hangboard training protocol combined with a structured finger extensor training protocol twice weekly for six weeks. Extensor training is performed at 70% of maximal finger extension strength using isometric loading, and will . Participants will complete pre-, mid-, and post-intervention testing of grip strength, finger flexion strength, finger extension strength, finger endurance, and self-reported upper extremity function.

Other: Traditional Hangboard Protocol; Other: Extensor Tendon Isometric Training

Control

NO INTERVENTION

Participants assigned to the control group will continue their usual climbing activities without participation in a structured finger training intervention. Participants will complete pre-, mid-, and post-testing identical to the intervention groups.

Interventions

Traditional Hangboard Protocol OTHER

A structured finger flexor strength training protocol performed on a climbing hangboard at 70% of maximal finger flexion strength. Training consists of 5 seconds of isometric loading followed by 5 seconds of rest for 6 repetitions per set, across 6 sets with 3 minutes rest between sets. Training is performed twice weekly for six weeks following a standardized upper extremity warm-up.

Maximum Extensor Strength (MES); Maximum Flexor Strength (MFS)

Extensor Tendon Isometric Training OTHER

A structured finger extensor tendon training protocol performed at 70% of maximal finger extension strength using isometric loading. This intervention will be in addition to performing the Finger Flexor Protocol. Training consists of 30-second isometric contractions with 3 minutes of rest between sets for a total of 6 sets per hand. Training is performed twice weekly for six weeks and is completed during rest periods of the finger flexor training protocol

Maximum Extensor Strength (MES)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults aged 18 years or older
• Recreational to advanced rock climbers as defined by the International Rock Climbing Research Association (IRCRA) scale
• Climbing experience of at least 1-2 sessions per week for the past 6 months OR a minimum of 2 years of climbing experience
• Ability to commit to two 45-minute training sessions per week for 6 weeks
• Access to a hangboard or fingerboard and appropriate loading equipment
• Ability to provide informed consent
• Willingness to refrain from climbing the day prior to testing sessions

You may not qualify if:

• Upper extremity injury (hand, wrist, elbow, or shoulder) within the past 6 months
• Participation in a structured or organized hangboard training protocol within the past 4 months
• Climbing less than 1-2 times per week during the past 6 months and less than 2 total years of climbing experience
• Age under 18 years
• Inability to safely perform maximal isometric finger flexion or extension testing
• Inability or unwillingness to comply with the study protocol

Sponsors & Collaborators

• April Henderson: lead

Study Sites (1)

Mazamas

Portland, Oregon, 97215, United States

Location

Related Publications (11)

• Valenzuela M, Launico MV, Varacallo MA. Anatomy, shoulder and upper limb, hand lumbrical muscles. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534876/

  BACKGROUND

• Colzani G, Tos P, Battiston B, Merolla G, Porcellini G, Artiaco S. Traumatic extensor tendon injuries to the hand: Clinical anatomy, biomechanics, and surgical procedure review. Journal of Hand and Microsurgery. 2016;8(1):2-12. doi:10.1055/s-0036-1572534

  BACKGROUND

• Johnson MA, Polgar J, Weightman D, Appleton D. Data on the distribution of fibre types in thirty-six human muscles: An autopsy study. Journal of the Neurological Sciences. 1973;18(1):111-129. doi:10.1016/0022-510X(73)90023-3.

  BACKGROUND

• Salonikidis K, Amiridis IG, Oxyzoglou N, Giagazoglou P, Akrivopoulou G. Wrist flexors are steadier than extensors. International Journal of Sports Medicine. 2011;32(10):754-760. doi:10.1055/s-0031-1280777.

  BACKGROUND

• Hägg GM, Milerad E. Forearm extensor and flexor muscle exertion during simulated gripping work: An electromyographic study. Clinical Biomechanics. 1997;12(1):39-43. doi:10.1016/S0268-0033(96)00049-6.

  BACKGROUND

• Lum D, Barbosa TM. Effects of isometric strength training on strength and dynamic performance. International Journal of Sports Medicine. 2019;40(6):363-375. doi:10.1055/a-0863-4539.

  BACKGROUND

• Vigouroux L, Quaine F, Labarre-Vila A, Moutet F. Estimation of finger muscle tendon tensions and pulley forces during specific sport-climbing grip techniques. Journal of Biomechanics. 2006;39(14):2583-2592. doi:10.1016/j.jbiomech.2005.08.027

  BACKGROUND

• Leung J. A guide to indoor rock climbing injuries. Current Sports Medicine Reports. 2023;22(2):55-60. doi:10.1249/JSR.0000000000001036

  BACKGROUND

• Philippe M, Wegst D, Müller T, et al. Climbing-specific finger flexor performance and forearm muscle oxygenation in elite male and female sport climbers. European Journal of Applied Physiology. 2012;112:2839-2847. doi:10.1007/s00421-011-2260-1

  BACKGROUND

• Saul D, Steinmetz G, Lehmann W, Schilling AF. Determinants for success in climbing: A systematic review. Journal of Exercise Science and Fitness. 2019;17(3):91-100. doi:10.1016/j.jesf.2019.04.002.

  BACKGROUND

• Devise M, Pasek L, Goislard De Monsabert B, Vigouroux L. Finger flexion to extension ratio in healthy climbers: A proposal for evaluation and rebalance. Frontiers in Sports and Active Living. 2023;5:1243354. doi:10.3389/fspor.2023.1243354.

  BACKGROUND

Related Links

• Critical Force Calculations
• Emil Abrahamsson No Hangs Protocol Warm up Routine

Study Officials

• Chuck Ruot, PhD

  Hardin-Simmons University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: co-investigator

Model Details: This is a three-arm, parallel-group randomized controlled trial with repeated measures. Participants are randomly assigned to one of three groups: traditional finger flexor training, combined finger flexor and extensor training, or a control group continuing regular climbing without intervention. Outcomes are assessed at baseline, mid-intervention (3 weeks), and post-intervention (7 weeks)

Study Record Dates

• First Submitted: February 11, 2026
• First Posted: February 17, 2026
• Study Start: November 11, 2025
• Primary Completion: April 4, 2026
• Study Completion: April 6, 2026
• Last Updated: February 18, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)