Patient generated forces refer to the internal muscular forces produced by the patient through their own voluntary actions or physiological processes. These forces include voluntary movements such as pushing or pulling, breathing, and the body’s inherent / involuntary ability to self-correct.

Such internal forces exerted by the patients on their own body segments as an intervention are called as ‘patient generated forces’.

For example, muscle energy techniques rely on patient generated internal muscular forces because the patient actively generates and controls the force applied on their own body segments. However, the clinician may also need to apply an equal and opposite (clinician generated external) force to achieve the desired therapeutic effect. Such external forces exerted by the clinicians on a human body segment (through techniques like thrusts, as well as the influence of gravity or mechanical devices) as an intervention are called as ‘clinician generated forces’.

Muscle Energy Technique

Muscle energy techniques depend on the patient generated internal forces, as the patient actively produces and manages the force applied.

In muscle energy techniques, a patient might be asked to actively contract a muscle against a clinician’s resistance. For example, if a patient has a restricted range of motion in their shoulder, the clinician might instruct the patient to push their arm against a stationary surface (or the clinician’s hand) as hard as they can. Although the clinician might also need to apply a counteracting (clinician generated) force to achieve the therapeutic goal, these forces generated by the patient’s own efforts on their body segments are referred to as ‘patient-generated forces.’

Here’s how it works:

Action by the Patient: The patient generates an internal force by contracting the shoulder muscles and pushing against the resistance provided by the clinician.

Response by the Clinician: The clinician applies an equal and opposite force to the patient’s push. This counteracting (clinical generated) force helps in guiding and controlling the motion, ensuring the patient does not exceed safe limits.

Therapeutic Effect: The patient-generated force helps in mobilizing the restricted shoulder joint, promoting tissue relaxation and improving the range of motion.

In this scenario, the force generated by the patient’s muscle contraction is termed a patient-generated force.

Breathing Exercises for Diaphragmatic Strengthening

In the context of respiratory rehabilitation, patient-generated forces are often used to strengthen the diaphragm and improve breathing efficiency.

Action by the Patient: The patient performs deep breathing exercises, focusing on diaphragmatic breathing. During these exercises, the patient actively contracts the diaphragm muscle to draw air into the lungs, expanding the abdomen and chest.

Self-Generated Force: The force exerted by the diaphragm to expand the lungs and create negative pressure is an example of a patient-generated force. This internal force helps to improve lung capacity and breathing mechanics.

Therapeutic Effect: Regular practice of these breathing exercises enhances diaphragmatic strength, improves respiratory function, and can aid in recovery from respiratory conditions or surgeries.

In this example, the patient-generated force is the contraction of the diaphragm during the breathing exercises, which is essential for achieving the therapeutic goals of respiratory rehabilitation.

Isometric Muscle Contractions

In rehabilitation settings, isometric exercises are often used to improve muscle strength and joint stability.

Action by the Patient: Suppose a patient is recovering from a knee surgery and is performing isometric knee extension exercises. The patient is instructed to extend their leg and push against a stationary object, such as a wall or the floor, without changing the angle of the knee joint.

Self-Generated Force: In this exercise, the patient generates an internal force by contracting the quadriceps muscles to push against the resistance provided by the stationary object. This force is entirely produced by the patient’s muscle contraction without any movement at the joint.

Therapeutic Effect: The isometric contraction helps strengthen the quadriceps muscles, improve joint stability, and reduce pain or stiffness in the knee, aiding in the recovery process.

In this scenario, the internal force generated by the patient’s isometric muscle contraction is an example of a patient-generated force.

Resistance Training with Body Weight

In resistance training, body-weight exercises are a common example of patient-generated forces.

Action by the Patient: Consider a patient performing a plank exercise to strengthen the core. During this exercise, the patient maintains a position with their body straight and supported on their forearms and toes, engaging the core muscles to hold the position.

Self-Generated Force: The internal force generated by the patient comes from contracting the abdominal, back, and gluteal muscles to maintain body alignment and stability against the force of gravity. This force is entirely produced by the patient’s own muscles working to support and stabilize their body.

Therapeutic Effect: This self-generated force enhances core strength, improves posture, and provides stability to the spine, contributing to overall functional strength and injury prevention.

In this example, the patient’s muscle contractions to resist gravity and maintain the plank position are considered patient-generated forces, illustrating how these forces are used in resistance training to achieve therapeutic goals.

In summary, the application of physical forces to human body segments are critical as they impact movement patterns, tissue adaptation, and functional outcomes. Mastering the application and management of physical forces (both clinician and patient generated) during rehabilitation is crucial for diagnosing conditions, refining treatment strategies, and enhancing recovery. Using biomechanical principles, therapists can tailor the application of physical forces to diagnose, treat impairments, improve function, and promote the best possible outcomes for patients recovering from injury, surgery, or neurological conditions.