Electrical Muscle Stimulation for Speed & Strength Development:

Research Findings & Practical Applications

Derek M. Hansen, CSCSwww.StrengthPowerSpeed.com

Personal Background with EMS

• EMS and TENS applied as an athlete in rehab context – limited efficacy as currently applied

• Used EMS for personal strength development in early 1990’s with great success

• Began applying as a coach in late 1990’s – primarily on sprinters – speed, strength and recovery

• Currently own 7 portable stim units for various purposes

• Used extensively by CF during 1980s with his sprint athletes

• Protocols based on Yakov Kots’ research and presentation in Concordia University in Montreal in 1977

• CF worked with Waldemar Matuszewski – PhD in electrostimulation from Poland

• Learned a significant amount regarding planning and use of EMS with speed athletes – 2001-2010

Charlie Francis and EMS

• “10-50-10”• Kots and Xvilon – Two-part study, not using

2.5 kHz AC, but rather using short-duration (1 millisecond) rectangular PC at a frequency of 50 Hz

• 10/50/10 regimen was optimal as a 10 minute training session done daily or every second day for a period of 9-19 days

Kots’ Protocols

• Electrically induced fatigue was noted at a mean of 12.5 seconds, after which it progressed rapidly – thus chose 10 seconds

• Compared “off” times of 10, 20, 30, 40 and 50 seconds

• 30 sec or less – average torque during second set was less than torque during the first set and fatigue increased during the second 10-second set. Thus – chose off time of 40-50 seconds.

Kots’ Protocols

• Kots argued that EMS preferentially recruits fast-twitch, fast-fatiguable motor units Axons of larger motor units have lower

resistance to current and conduct action potentials at a faster rate than smaller motor unit axons

Data demonstrate increased fatigue with EMS versus voluntary activation

Kots’ – Recruitment Order

• Gregory and Bickel (2005) - majority of evidence suggests that EMS-induced motor unit recruitment is non-selective and that muscle fibers are recruited without obvious sequencing related to fiber types

• Faster conductivity for direct stimulation (in vitro or in situ) but not for cutaneous EMS – thus resulting in a more random pattern of recruitment (Kim et al)

• Preferential recruitment only held true approx. 30% of trials – not all the time (Feiereisen et al)

Kots – Recruitment Order

• Many of the conclusions on recruitment order were based on in vitro or in situ animal studies

• Does not apply to practical use by humans due to skin impedance, subcutaneous fat, peripheral nerve orientation, etc.)

Kots – Recruitment Order

• Kots was mostly right…• His protocols are not written in stone and can be

modified for optimum results• Athletes respond better to a progression of work• Always monitor the status of the athlete day to

day – making appropriate adjustments as necessary

Kots – Lessons for Moving Forward

• Technology has improved• Portable stimulators as effective, more convenient

and efficient• Use of EMS must be well integrated into the

conventional training plan• “More pain = more gain” not applicable today• Numerous rehab applications• Easy to use – Not only for “certified” therapists.

Strength coaches may be more qualified due to their knowledge of strength programming and adaptation.

What I’ve Learned

• Planning intensive approach• Identified optimal frequencies and pulse

widths• Emphasized gradual progression, optimal pad

placement and recovery times• EMS is a supplement to good training – not

replacement

SpeedCoach Project with Globus

• Ideal frequencies – 80 Hz to 100 Hz – for athlete population• Sample progression:

Speed 1: Sessions 1 and 2 at 80Hz- 8 min pulsing warm-up at 5 Hz- 4 sets of 4 seconds on, 20 seconds off- 5 sets of 7 seconds on, 35 seconds off- 6 sets of 10 seconds on, 50 seconds off Total Time Under Contraction = 111 secondsTotal Program Time = 18 minutes 16 seconds

SpeedCoach Project with Globus

• Athletes need to “warm-up” to the idea of involuntarily and maximally contracting their muscles

• Shorter duration contractions on initial sets• Gives them time to locate the appropriate

intensity for contractions

SpeedCoach Project with Globus

Speed 4: Session 7, 8 and 9 at 100Hz- 8 min pulsing warm-up at 5 Hz- 5 sets of 6 seconds on, 30 seconds off- 10 sets of 10 seconds on, 50 seconds off- 8 min pulsing cool-down Total Time Under Contraction = 130 secondsTotal Program Time = 25 minutes 10 seconds

SpeedCoach Project with Globus

• DeVahl has reported that increased distance between electrodes produces greater current penetration into stimulated muscle.

• The resistance to skeletal muscle current flow is least when the current is applied parallel to muscle fibers which improves EMS comfort and tolerance.

• Place one electrode over a motor point and the other at the distal end of the muscle in an orientation that is parallel to the muscle fiber arrangement.

Crossing Pad Placement

• For fusiform muscles (i.e. biceps brachii), the greatest distance between electrodes results in current flow running parallel to the muscle fibers.

• In penniform muscles of the quadriceps, a longitudinal arrangement between electrodes does not result in the current flow being parallel to muscle fibers. It is possible, however, to increase the distance between electrodes and improve the parallel orientation of the current to the fibers if the distal electrode is placed on a synergistic muscle group.

Crossing Pad Placement

Biceps Brachii

Quadriceps

• Barnett et al. reported greatest quadriceps torque using a single pair of electrodes placed diagonally across the R. femoris, V. lateralis, V. intermedius, and V. medialis motor points from the proximal V. lateralis to the distal V. medialis.

• Peak torque during the X treatment was significantly greater than the peak torque during the P treatment.

X treatment = 57.2 +/- 2.5% P treatment = 46.5 +/- 2.4%

Crossing Pad Placement

• Post-Surgery ACL – Quadriceps Strengthening Immediate post-surgery – Pulsing on

quadriceps (activation and edema reduction) 1-2 weeks after surgery – 4 second

contractions, 20 second recoveries 3 weeks after surgery – 6-10 second

contractions, 30-50 second recoveries 4-6 weeks after surgery – superimposed

squatting – concentric phase initially

Return-to-Play Applications

• Active recovery sessions Post-workout Pre-game circulation (on bus or airplane) Post-game recovery (on bus or airplane)

• Maximal Strength Sessions Resets muscle tone Athletes reported generally feeling greater

muscle loosening after max-strength EMS sessions

Recovery & Regeneration Applications

For more information, please visit:

www.StrengthPowerSpeed.com

Thank you!