Mini-Study: Loaded vs. Unloaded Mobility — MTI Finds No Change in FMS Scores After 4 Weeks

By Sam Johnson

BLUF (Bottom Line Up Front)

Over a 4-week cycle, four MTI Lab Rats tested a mobility training protocol to explore the effectiveness of loaded vs. unloaded dynamic mobility exercises. Mobility was assessed via a modified FMS Overhead Squat test, using increasing heel elevation to gauge range of motion (0–25 lb plates).

Despite training 3x/week, none of the participants improved enough to reduce their required heel elevation, and no quantifiable improvements were observed in test scores. Slight visual improvements were noted in two participants, but these were not sufficient to shift assessment outcomes.

This suggests that while loaded mobility training may feel subjectively beneficial, more time, increased frequency, or different mobility protocols may be required to produce meaningful, measurable improvements in deep-range mobility or foundational movement patterns.

Key Participant Outcomes (FMS Overhead Squat Test)

Study Purpose

This mini-study builds on previous MTI mobility experiments that tested the effects of movement patterning, static stretching, and range-focused strength work.

The goal here was to compare two versions of a dynamic mobility protocol:

• Unloaded mobility (bodyweight-based mobility work)

• Loaded mobility (same movements with added resistance)

Primary Question: Would either approach improve squat mobility, as measured by heel elevation changes in the modified FMS Overhead Squat?

Training Protocol

• Duration: 4 weeks

• Frequency: 3x/week (Monday, Wednesday, Friday)

• Timing: Performed during or after squat sessions

Unloaded Mobility Group (Jackson, Emmett)

• 3×5 Knee Over Toe Split Squat

• 3×5 Front Foot Elevated Split Squat

• 3×5 Unweighted Pullovers (on foam roller)

Loaded Mobility Group (Sam, Song)

• 3×5 KB Knee Over Toe Split Squat

• 3×5 DB Front Foot Elevated Split Squat

• 3×5 Plate Pullovers (on foam roller)

All participants were instructed to increase their range of motion weekly and to progressively load or intensify the stretch as tolerated.

Results

• No participants decreased their required heel elevation in the FMS Overhead Squat test.

• Sam and Jackson showed slight visual improvements in depth and torso position, but these did not meet the threshold to reduce heel elevation.

• Song and Emmett displayed no visible or measurable change.

The results align with previous MTI mobility research indicating that short-term, low-dose protocols are often insufficient to shift underlying movement patterns — especially when measured with binary scoring systems like the FMS.

Discussion

This mini-study reinforces a common observation across MTI mobility cycles: subjective improvements and perceived range gains may not be reflected in objective test outcomes.

A few potential factors may explain the lack of measurable progress:

• Training dose was likely too low. At 3x/week and ~15 minutes per session, the intervention may not have provided enough frequency, intensity, or duration to create long-term tissue change or neuromuscular adaptation.

• Assessment sensitivity may be limited. The FMS Overhead Squat relies on discrete heel elevations (in 5–10 lb plate increments), which may not detect smaller mobility gains unless a participant crosses the threshold into a lower plate category.

• Protocol duration may have been too short. Four weeks may not be long enough for changes in deep-range motor control, joint capsule mobility, or connective tissue remodeling — especially when squatting and other high-load training sessions are also present in the training week.

• Loaded vs. unloaded mobility may not be the defining variable. Both groups experienced similar outcomes, suggesting that load itself was not a determining factor in short-term gains.

While some visual improvements were noted — particularly in squat depth and spine position — these did not translate to plate changes or measurable test score shifts.

Next Steps

In line with MTI’s iterative approach to mobility training and assessment, the following next steps are recommended:

• Increase training dosage and duration. Future mobility protocols should be extended to 6–8 weeks with at least 4–5 weekly exposures, especially for athletes struggling with deep range or hip/ankle limitations.

• Introduce tissue-prep mobility circuits pre-squat. Pairing mobility work with loaded squatting may prime the nervous system but could also blunt mobility focus. A revised protocol could test mobility-only sessions, performed standalone, to isolate impact.

• Test alternative protocols — such as long-duration isometrics (e.g., couch stretch holds, squat holds), dynamic banded joint distraction, or PNF (proprioceptive neuromuscular facilitation) stretching. These have shown promise in prior MTI work and may be more effective than low-volume dynamic sets alone.

• Reassess the assessment tool. Future mini-studies could trial more sensitive or granular mobility assessments (e.g., ankle dorsiflexion test, deep squat video analysis with angle tracking) to detect subtle changes missed by binary scoring models like FMS.