Relative Flexibility: Understanding Compensatory Movement Patterns and Injury Prevention

What is an example of relative flexibility?

Relative flexibility describes the body's tendency to choose the path of least resistance during movement, often due to muscle imbalances, leading to compensatory patterns in other joints or segments. A prime example is an individual with limited ankle dorsiflexion who compensates by excessively extending their lumbar spine during an overhead squat, rather than achieving depth through appropriate ankle and hip flexion.

Understanding Relative Flexibility: A Core Concept

Flexibility, in its broadest sense, refers to the absolute range of motion available at a joint or series of joints. However, relative flexibility introduces a critical nuance: it's not just about how much a joint can move, but how the entire kinetic chain moves during a complex action. This concept highlights that the body will always seek the most efficient, or "least resistant," pathway to complete a movement, even if that pathway is biomechanically suboptimal.

When certain muscles or joints are stiff, tight, or underactive, the body will naturally redistribute the movement demand to areas that are more mobile or less restricted. This compensation, while allowing the movement to occur, can place undue stress on other joints and tissues, potentially leading to pain, injury, and decreased performance over time.

The Classic Example: The Overhead Squat Assessment

The overhead squat is a foundational movement pattern that requires significant mobility and stability throughout the entire kinetic chain, from the ankles to the shoulders. It serves as an excellent diagnostic tool for identifying relative flexibility issues.

Consider an individual performing an overhead squat:

• The Ideal Movement: In a biomechanically sound overhead squat, the hips, knees, and ankles flex simultaneously, the torso maintains a relatively upright position, and the arms remain overhead in line with the torso, all while the feet stay flat on the ground.
• Relative Flexibility in Action:
  • Limited Ankle Dorsiflexion: If the individual has tight calf muscles (gastrocnemius and soleus) or a restricted ankle joint, their ankles may not be able to adequately dorsiflex (bend forward). To compensate and still achieve squat depth, the body will often shift the weight forward onto the balls of the feet, cause the heels to lift, or, more commonly, trigger excessive lumbar spine extension (arching the lower back) and/or an excessive forward lean of the torso. The lumbar spine and hips provide the "path of least resistance" to achieve depth when the ankles are restricted.
  • Tight Hip Flexors and/or Adductors: If the hip flexors (e.g., psoas, rectus femoris) are tight, they may limit hip extension and contribute to an anterior pelvic tilt. During the squat, this can manifest as the knees caving inward (valgus collapse) and/or the feet externally rotating as the body tries to find an easier way to descend. The adductors (inner thigh muscles) may also be tight, pulling the knees inward.
  • Tight Latissimus Dorsi and/or Pectoralis Major: When holding the arms overhead, tight lats or pecs can pull the arms forward and down. To keep the arms overhead and aligned with the torso, the individual might compensate by excessively arching the lower back (lumbar extension). This allows the arms to appear "overhead" relative to the torso, but it's achieved by hyper-extending the spine rather than through optimal shoulder and thoracic mobility.

In each of these scenarios, a specific joint or muscle group lacks the necessary flexibility, and consequently, another part of the body moves in an altered, compensatory manner to complete the movement. This is the essence of relative flexibility.

Why Relative Flexibility Matters for Performance and Injury Prevention

Understanding and addressing relative flexibility is crucial for several reasons:

• Movement Efficiency: Compensatory patterns reduce the efficiency of movement, requiring more energy expenditure for the same task.
• Altered Movement Patterns: Over time, these compensations can become ingrained, leading to chronic altered movement patterns that negatively impact daily activities and athletic performance.
• Increased Injury Risk: When certain joints are forced to move beyond their optimal range or in planes they're not designed for, it places excessive stress on ligaments, tendons, and joint capsules. This can lead to common injuries such as:
  • Low back pain (due to excessive lumbar extension)
  • Knee pain (due to valgus collapse)
  • Shoulder impingement (due to poor overhead mechanics)
  • Plantar fasciitis (due to altered foot mechanics)
• Synergistic Dominance: Relative flexibility issues often contribute to synergistic dominance, where prime movers are inhibited (altered reciprocal inhibition), and synergists (helper muscles) are forced to take over their role, leading to overuse and tightness.

Addressing Relative Flexibility Imbalances

Correcting relative flexibility requires a comprehensive approach, often following a systematic strategy like the National Academy of Sports Medicine's (NASM) Corrective Exercise Continuum:

• Inhibit: Use techniques like self-myofascial release (SMR) or foam rolling to decrease overactivity in tight, overactive muscles (e.g., calves, hip flexors, lats).
• Lengthen: Apply static stretching or neuromuscular stretching (e.g., PNF) to increase the extensibility of these same overactive muscles.
• Activate: Strengthen the underactive or weak muscles that are often inhibited by the overactive ones (e.g., anterior tibialis, gluteus medius, deep core stabilizers).
• Integrate: Re-train the body to move efficiently through integrated, multi-joint movements that reinforce proper movement patterns (e.g., goblet squats, deadlifts, overhead presses with proper form).

A thorough movement assessment by a qualified fitness professional or physical therapist is essential to accurately identify specific relative flexibility imbalances and design an individualized corrective exercise program.

Conclusion: Optimizing Movement Through Awareness

Relative flexibility is a powerful concept that moves beyond simple range of motion, emphasizing how different body segments interact during functional movements. Recognizing examples like the compensations seen in an overhead squat allows us to identify the underlying muscular imbalances that contribute to poor movement quality, decreased performance, and increased injury risk. By systematically addressing these imbalances, individuals can optimize their movement patterns, enhance their physical capabilities, and promote long-term musculoskeletal health.