What a camera can see in a kettlebell swing
A kettlebell swing loads through a hip hinge and finishes with an explosive hip extension. The rubric scores those as two independent criteria of equal weight: the smallest hip angle reached on the backswing, and the largest hip angle at the top. Both need a side or oblique view. The identity gate rejects clips where the knees bend past a squat threshold, because a swing driven by the legs is a different movement and would score misleadingly well on hip extension alone.
How ScoreRep scores a kettlebell swing
The rubric declares 4 scored criteria. The strongest single camera angle is the left side view. Every criterion below is available from that angle.
The score is the points earned divided by the points the recorded angle could support, so a clip filmed from a limited angle is never quietly marked down for what the camera could not see. At least 60% of the applicable weight has to be measured before a result is ranked at all.
| Criterion | Points | Measured from the athlete’s pose | Full marks when |
|---|---|---|---|
| Hip hinge on the loading phase | 30 | smallest hip angle in the rep | 60° or less |
| Hip extension on the drive | 30 | largest hip angle in the rep | 172° or more |
| Cadence | 20 | repetitions completed per second | 0.5 or more |
| Consistency across the set | 20 | drop in rep speed between the fastest and the slowest rep | 10% or less |
Criteria that depend on the camera angle
These criteria are excluded, not estimated, when the recorded angle cannot support them. That is why the same set filmed twice from different positions can produce two valid scores out of two different totals.
- Hip hinge on the loading phase — needs a left side, right side, left oblique and right oblique view.
- Hip extension on the drive — needs a left side, right side, left oblique and right oblique view.
Does this kettlebell swing rep count?
ScoreRep answers that in two separate steps. First, the clip has to read as a kettlebell swing at all: every check in the table below has to pass, and a reading the camera could not take counts as a fail, never as a pass. A clip that fails is returned unranked with the reason attached, rather than scored low against the wrong rubric, and no template can override a failed check.
Second, the scoring criteria award points. Falling short of a full-marks threshold costs points, not the rep. Every number here is read from version 1 of the kettlebell swing rubric, the same file the scoring engine runs.
- Compare the kettlebell swing standard with the other 29 movements on the movement standards page.
- How the rep counter decides between a valid rep and a no-rep, station by station.
| Reading | Has to be | Otherwise rejected because |
|---|---|---|
| Vertical travel of the hips across the rep | 0.05 or more | no clear hip hinge was detected |
| Largest hip angle in the rep | 155° or more | there is no explosive hip extension |
| Vertical travel of the wrists across the rep | 0.06 or more | the wrists do not travel vertically, so no kettlebell swing was detected |
| Smallest knee angle in the rep | 100° or more | the knees bend too much, which reads as a squat rather than a kettlebell swing |
What the recording has to contain
Eligibility decides whether a result can enter a leaderboard. Failing it does not block the feedback — the clip is still scored and returned, but marked unranked with the reason attached, so a bad camera position never silently becomes a bad score.
- A pose has to be detected in at least 55% of the frames.
- The camera angle has to be one of: left side, right side, left oblique and right oblique.
- At least 1 complete repetition has to be detected.
What is deliberately not scored
Identity, repetition counting, eligibility and the score are derived only from the athlete’s pose. Measurements that come from tracking an external object — the path of a barbell, for example — are drawn on the review overlay but are deliberately outside the scoring contract, so they never affect the number.
Reading the result
The two hip criteria are worth reading as a pair. A deep hinge with a weak finish means the athlete is lifting the bell with the arms; a shallow hinge with a strong finish usually means the backswing is being cut short to keep the pace up. Cadence and consistency exist to make the second pattern visible over a long set, where a single-rep view would miss it entirely.
A technique score is educational feedback about visible movement. It cannot tell you whether a load is safe for your joints, whether pain means something, or whether a programme suits you. Those judgements need a coach or clinician who knows your history.