Contraction Sensitivity Isometrics™


CSI’s are the skilled elicitation of a strategic sequence of static contractile responses to a series of light forces applied manually in strategic direction and response-sensitive magnitude to both the agonistic and the antagonistic muscles surrounding a joint in their shortest and longest ends respectively.

Importance in Exercise

The primary purposes for CSI’s:

  1. The initial step in PPFC Progressive Preparation For Challenge (as a substitute for stretching)
    1. Introduces the joint/s and associated co-contracting musculature to the direction of resistance of the exercise allowing it the opportunity to progressively orchestrate the required tensions around the joint/s
  2. Potentially influences the “current settings” in the positional extremes that represent the ends of the Exercise Specific AROM and the associated contractile lengths
  3. An opportunity to assess the joint control at the current extremes of range in a highly sensitive manner
  4. May be employed as a low-level exercise/stimulus if needed to progress excessively deconditioned contraction near end ranges (i.e. to improve near-zero levels of tension production)


CSI Procedures

  1. Joint positions are determined by the exercise to be performed. Understanding (not memorization) of musculoskeletal anatomy, joint mechanics can be helpful, but are not required, however, the ability to define the viable positions for the specific exercise is vital.
  2. Introduce a body position that eliminates the need for contraction (removes or reduces the client’s active limb control requirements) at the involved joint/s as much as possible. Manual support from the practitioner is critical and must be highly sensitive and skilled. The client must feel secure in the practitioner’s support of the limb in order to relax.
  3. Client moves actively to a comfortable, non-straining position associated with full shortening of the agonists (as defined by the resistance / TOW).
    1. He/she should be able to stay there or it’s not comfortable and non-straining.
    2. Maintaining the static positions of all other joints is critical to contractile precision.
    3. Support or positional changes (body in space) may be required to reduce effort, the influence of other muscles, or influence of gravity pulling into an uncomfortable position.
    4. Excessive force, excessive range, or even the action of other muscles involved in holding the limb may incite protective responses and diminish the effect.
  4. Check contractile control “into” that range
    1. Into = manual force applied to shortened side directed out of the position of shortening.
    2. Client only holds. (“hold right there”, “keep this precise position”) Not “arm wrestling”. Not trying to “win”.
      1. Client does not guess at a percentage of effort to produce; merely meets the minimal load offered with an commensurate effort
      2. Most clients will default toward aggressiveness and do too much if not continually reminded to “just hold”.
    3. Practitioner gently applies mere ounces of force tangential to the limb and in the plane for slow 6-8 count.
      1. The exact time is less important than monitoring of the effect.
      2. It is not to be fatiguing in any way.
    4. This procedure cannot be performed independently against one’s own “internal stops” as this is likely to illicit protective responses
    5. Remain in this exact position (precise contractile lengths) for the next step.
  5. Check contractile control “out of” that position (traditional PNF)
    1. Apply same level of force to the lengthened side / antagonist
  6. Assess for any increased opportunity to move further into the shortened position with the same degree of comfort i.e. “take up the slack.”
    1. Range may change.
      1. If primary the influence in the current position is current settings/acute conditioning then it may change.
      2. Given that range is really about contractile length, shortening may occur microscopically with no visible change in joint position.
    2. Range may not change. Procedure is still successful.
      1. Not attached to or emotional about lack of change
      2. Could be structural normal, abnormal
      3. Or orchestrated muscular protection currently necessary
      4. Either way we have started our orchestration and PPFC
    3. Do not stray from the original positions or new position between isometrics
      1. This makes it easier to assess minor changes in position if any
      2. If the position can’t be maintained then the “comfort” rule was violated or the force applied was too great.
      3. If in fact it is challenging even at the lowest level force, then it has become your first exercise.
  7. Perform the first procedure checking contractile control “into” the range again.
    1. This will confirm the contractile integrity in the new position of shortening and can be the conclusion of the series.
    2. If the first series produced considerable change the decision may be made to proceed through another series, in which case proceed to number 8.
  8. If you do another antagonist/lengthened contraction, then check for more range again and follow up with another short end/agonist contraction into the range.
    1. Start and end with agonist (short end) contraction.
    2. Therefore can be a total of 3, 5, etc. total isometrics combined
    3. i.e. short side, long side, assess, short side / long side, assess, short side
  9. Now you should go to the other end of that plane/range and assess the antagonist in its shortest position and the agonist in its longest.


Remember the use of the words agonist and antagonist above are based upon the exercise for which one is preparing.


Common Mistakes


CSI should not be confused as being similar to or conflicting with MAT Jump Start. Each serves entirely different purposes and are entirely dissimilar procedures. In fact the two work well in concert i.e. during the “warm up” (PPFC) CSI may help to identify a specific reason for performing MAT prior to loading.

Purpose Progressive Preparation for ChallengePotentially alter “Current Settings” Low-level stimulus for near-zero contraction Identify and remedy weak positions
Positions Determined by the plane of the exercise and client comfort/sustainability Predetermined / protocol
Amount of force Determined by practitioner sensitivity to client response Determined by client (e.g. “10%”) Predetermined by protocol (e.g. 25#’s)
Directions of force Ex specific; direction sequenced between agonist and antagonist Predetermined / protocol
If client can’t hold position the trainer pushed too hard! Back off, find the appropriate amount and progress them! If client can’t hold position they are weak

 Prefacing info: